


Gambit

by Teyke



Series: The Undone Universe [9]
Category: Marvel Cinematic Universe, The Avengers (Marvel Movies)
Genre: Alternate Realities, Alternate Universe – Canon Divergence, Anxiety, Gen, PTSD, Suicide, Time Travel
Language: English
Status: Completed
Published: 2015-11-28
Updated: 2016-04-29
Packaged: 2018-05-03 18:05:20
Rating: Mature
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 19
Words: 190,484
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5301446
Author URL: https://archiveofourown.org/users/Teyke/pseuds/Teyke
Summary: <blockquote class="userstuff">
              <p>The Living Tribunal has fallen. The multiverse itself is imperilled. At the eleventh hour, an unlikely saviour steps forward with a plan to prevent the multiverse’s destruction. </p><p>Tony promised Steve he would cooperate. But a promise made under duress is worth less than most—especially when all of creation is at stake...</p>
            </blockquote>





	1. Shield and Sword: 1.1

**Author's Note:**

> This fic is the last in a series and will probably not make much sense if you haven’t read the previous stories. The series diverges heavily after the end of The Avengers and is not canon-compliant with anything from Phase 2 or 3. 
> 
> This fic uses special formatting which may not download properly (it's readable, but the formatting is stripped) into epub/mobi/etc format. 
> 
> I owe an enormous debt of gratitude to my betas for this fic, Subjunctive and Laura, as well as the betas who have helped me with this series overall, Cy and V. I wouldn’t have made it without a lot of help.
> 
> 05/28/16: One final, wonderful [playlist](http://8tracks.com/kurukami/the-undone-universe-v-gambit) by [Kurukami](http://archiveofourown.org/users/Kurukami)! Track list is available [here](http://archiveofourown.org/works/5301446/comments/62455318). Thank you so much ♥

** PART 1: SHIELD AND SWORD **

**An eternity ago: the Early Universe**

Fifteen years of using the Time and Space Gems wasn’t enough to figure out all their tricks. Essential universal concepts were a pain in the ass like that. But it was enough to get the hang of using them to travel, and Tony had gotten used to having his brain flipped inside out and then pieced back together. He didn’t stumble on the landings anymore.

This time, however, he wasn’t the one in the driver’s seat—sort of—and the sharp fall through Time and Space was nauseating. Tony hit the ground and had to wheel his arms sharply to regain his balance, small repulsors forming on the palms of his hands and firing to keep him from landing on his ass.

_Christ, that was a stronger push than I really needed._

_...not like I didn’t give him adequate reason._

He was lucky he’d gotten to the right destination at all; he remembered that frame of mind. There was no mistaking this place, though. Grey mist hid what he knew from experience was a barren grey landscape. It wasn’t actually mist, and the temperature was a perfect 298, human room temperature, but some phantasmal  chill seemed to sink into his bones nonetheless—or maybe that was just weariness. It had been a long time since he’d first fallen into this dead realm, beat up and bruised and convinced he was dead. A lifetime ago in one direction, an eternity from now in the other... and if he’d taken Hel, the first one, up on her offer all those years ago...

_Then I wouldn’t be here now, and that wouldn’t actually be a good thing._

Tony breathed out tiredness and some small portion of giddy relief, and turned to face the throne. The girl upon it looked at him with a child’s curiosity and no alarm, and he gave her a small bow. “Care to exchange favours, lady?”

Her dead eyes didn’t brighten, but she sat up straight from her half-drowsing slouch. “Favours? I’ve never gotten to! Oh, I want—I want—” She paused, as indecisive as a kid confronted with a full bar at Baskin-Robbins.  

“A death,” he said, watching her for those signs of _other_. “A real, complete death, all the dying over and done with, The End. There’s not gonna be anything else around to die properly for another couple eons, so it’s a special opportunity you’ve got here.”

She regarded him mistrustfully, and sulked. “I can’t just _do_ that. No deaths, big or little, unless they ask for it.” Her words had the sing-song nature of a rule learned by rote, and the whining undertone of somebody who resented that rule. 

“I’m asking.”

“Oh!” She brightened again, then looked doubtful. “Really?”

“Really really. I'll ask you for it, right now. All I want in return is—put in a good word for me, with your Goddess, huh?” Favour he’d already enjoyed, Hel’s and Hers, paid for retroactively and in advance, here and now.

“Done,” she said promptly, greedily. “Now?”

For a moment he hesitated, survival instinct kicking in belatedly. _I’m really going to do this._ He had to. He already knew how it worked out if he did. If he hadn’t sent the Gems away already then he could have run despite that—the Time Gem could support paradoxes, it wouldn’t implode the multiverse if he ran away now. But it would _change_ things, as cause-and-effect rippled back and forth until the Time Gem could smooth them out, and after everything... this was exactly where he wanted to be.

In more ways than one.

 _Is this selfishness?_ It was a nagging thought, but unimportant. It didn’t really matter anymore if it was or wasn’t.

“Now,” Tony agreed, and felt more then saw the grey nothingness to his left deepen. Lighten? Darkness, the lack of light, was fading away just as much as the light itself. Less reality, less unreality, less everything, in a way that human brains—no matter how strange his was, now—weren’t designed to comprehend. This wasn’t the Ginnungagap, wasn’t the flip side of anything. It just _wasn’t._

“The beginning of the end,” said Hel with her slight child’s lisp, and there it was, that alien knowing— _no._ Not alien.

Godly, maybe.

“Say a prayer for me,” Tony told her. It was a struggle to keep his voice even in the face of that absolute end, that death, that erasure from everything.

 _I win,_ and the relief was _staggering_ , but he had to focus. It took effort, but he managed, forcing his own prayer—might as well call it what it was—uppermost in his mind. He’d only get one shot at this, after all.

If he screwed it up, the Time Gem would smooth that over too, and then they’d all be fucked.

_Hide what I will-am-have do-doing-done. Keep it secret._ Please.

Tony closed his eyes, praying, and took the last step left.  

 

* * *

 

**Five Minutes After An Eternity Ago**

Tony stumbled on the landing, managing to trip over nothing at all. Extremis-given grace let him catch his balance before he fell to the hard-packed, boring-boring-boring grey ground, so familiar—even if he’d flubbed the landing, at least he’d gotten the right place. Had he gotten the right time? Possibly he should have done a bit of practice with the Space and Time Gems first, rather than attempting to throw himself across the entire length of reality on his first real try.

He turned around, shaking off the lingering overawed feeling that came from using two lynchpins of creation to traverse the breadth and depth of the multiverse. What he saw was... not quite what he was expecting.

“Oh, I haven’t met you yet,” said Hel from where she was curled up in her throne. Both of her arms, still pudgy with baby-fat, were curled over one armrest, and now she smushed her chin into them, right on top of the skull embedded as part of the throne’s decoration. Her feet dangled above the ground. He didn’t have the best idea how fast young children aged, but if she’d been human, he’d have been surprised to hear she was older than five. Maybe six.

“That’s relative,” Tony told her.

“You want another fa-vour,” she sing-songed in her child’s voice.

He winced, fighting down the first beginnings of panic. Here was a child-god, queen of Helheim, and her father and uncle were two of the most vindictive bastards he’d ever had the misfortune of meeting—but for all that she’d tried to trick him into obliterating himself, once, at least she’d have made it painless. Right. He could deal with that. “Just to clarify, first favour. You haven’t done me any before.”

She smiled, a movement of the muscles around her mouth only.

 _Moving on, moving on -_ “You said—will say—that death keeps all secrets.” He watched her carefully, but she just hummed tonelessly, kicking her dangling feet back against her throne, a bored little girl. “I need to hide something, from... everything. Inside this cluster, and outside it. Everywhere. You’re the goddess of death. Can you do it?”

If this didn’t work—for a moment, panic gripped him. What if she'd just been boasting, in true Asgardian fashion? What he was asking for was bigger than anything he'd seen her do. If she couldn't pull it off—

Then he’d have to come up with something else. Failure wasn’t an option. But she was his best shot. She wasn’t limited to the bounds of the local cluster of multiverses, like the other Asgardians—“Death. Eternity. Infinity. _Inevitability.”_ She might be able to do it. If not—

For something this big, technology wasn’t going to cut it. It was a galling, bitter thought, but true.

“Nooo,” she sighed, drawing it out and looking disappointed. His heart sank. “That’s too big. You’ll have to ask Her yourself.”

Hope rose again. “Your goddess.”

“Goddess,” she corrected, and he could _hear_ the capital ‘G’. Her whole face lip up as she pronounced this word, and her smile stretched from ear to ear. There was satisfaction there to the deepest hunger, like when the edges lined up or dice rolled a pair or paving stones were _just_ long enough that he could continuously alternate which foot stepped across the cracks he walked over. Balance.

“Oh,” he said. He remembered looking back through time, and hearing what Loki had said about gods who worshipped other gods in turn—“All beings respect those with more power, except the very stupid. The merely stupid sometimes take it to ridiculous extremes — even among gods.” 

From what he was seeing in Hel’s eyes, maybe Loki was the very stupid one.

_...and that makes me..._

“I can send you to her,” Hel said coyly, leaning forward. She was toying with him; there was something he couldn’t read, in that look. “If you ask.”

“I can send myself, thanks,” said Tony, trying to think. He had the Time and Space Gems; no need to incur a favour over that. “Though directions would be handy.”

“‘s not a place,” she said, with a child’s slight lisp. “She is the End.”

_Oh._

“A long time ago... from now—you tried to trick me into obliterating myself. Oblivion, you called it.”

“The end,” she said, her head bobbing up and down on her skinny neck, a child’s enthusiastic nod. “This’s all—” Hel shrugged, and indicated her throne and all of the mist surrounding them with a big wheel of both arms. That was _wrong_ , a hands that skeletal on the arms of a child. When he didn’t look quite at her, she looked right, still a bit pudgy with baby-fat; when her gesture drew his focus to her limbs, he could see where the bones were ready to break through tightly-drawn skin.

“Here ‘s’all dying,” said Hel. “Decaying, ending. Body, then soul, then mind. We work toward Her. I do. I’ll never see Her, not directly.” She looked forlorn at this. “Not until the very last End. Everybody else has to go first, that’s what I do, the ones like me. So I could... send you there. If you ask.”

Send him there—by obliterating him mind, body, and soul. Right. He had a good start, he was already missing one of those. Or maybe that would be a problem instead: hard to destroy it when it was elsewhere...

“The soul’s kind of a problem.”

She looked at him, big eyes protruding from her wasted skull of a head. He carefully refocused his gaze to the probably-not-actually-air about a centimetre in front of her face. “Everything ends. Connections, too. I can break it.” 

“Great, next question,” said Tony, holding up a hand and trying to make it seem like it was due to the question, and not because he really wanted to back away from the enthusiasm giving life to those dead eyes. “How do I ask Her after I’ve stopped existing?”

“She knows already,” said Hel, sounding proud of her Goddess’ omniscience. “Thoughts end and words end and moments end. But you have to _ask_.”

“And if I just let you—obliterate me—”

“Ask,” she insisted.

Right. The Norns had told him, so long ago: there were restrictions on death gods. Maybe there were restrictions on Death Herself, too.

“If I ask you, to let me see Her, will She agree?”

Again, that nauseating head-bobble, so emphatic that he expected her skull to fall off her neck. Somehow, it stayed on. “She likes hiding things and secrets and stuff. Thanos keeps trying to _find_ Her and She doesn’t like him at _all_.” Surely no eye-roll should show so much of the sclera. “And she likes _you_ —”

“Really?”

“Yes,” Hel said firmly. “And I’ll say please, too, and you’ll be my very first real End.”

“Right,” said Tony. He coughed to clear his throat, and give himself time to think. Was he doing this? Trusting to the whims of a... what? A God? A concept?

_Only two constants, death and taxes._

Everything dies in the end. 

A different version of Hel, from a different cluster of multiverses, had tried to trick him into this exact thing, once. And here he was, thinking of asking her to do it. But that Hel had been trying to save her cluster; she’d been the only one, apparently, able to figure out Loki was up to something. If she’d succeeded in tricking him, her cluster might not now be spiraling down into the endless abyss—neither able to reach a final End, nor burn to ash and be reborn.

And he wouldn’t be here now, to bargain for _this_ cluster’s salvation.

Hel looked at him, waiting with more patience than any tiny child should have. Her eyes were fathomless pits in her face.

_Alright. I’m going to do this. How?_

Implementation was going to be tricky. It wasn’t that he was scared of total obliteration. Far to the contrary: god knew he’d considered it often enough for way more selfish reasons, and when the time came it might even be a relief—he shut down that line of thinking and considered the problem at hand. He already had one date with annihilation. With the Time Gem, being in two places at once was easy, but _dying_ in two different places was still going to be a trick. Couldn’t exactly loop back on himself after the fact.

  _I’ll need someone else._

Tricky. Loki was still waiting for him, no doubt, to return to his own present—when looking back along the Time Gem he’d caught glimpses of what might be waiting for him there. Trying to unravel Loki’s traps would put him too close to springing them. It was what had sent him running to the start of the universe.

_Can’t be Steve. Can’t be one of the others. Someone else._

He ran through scenarios. The spread of information needed to be contained, first of all. Even if he could bargain for Death to pull Her cloak over any plan he could come up with, he doubted that would help if someone simply blurted it out loud. Loose lips sank ships. So. That could be limited. But no matter which way he turned it around, there was no escaping the fact that he was going to have to set any plan in motion before coming back to beg secrecy. He had to toss the dice and hope that Death really did like him.

_If it all falls apart, I’ll just have to redo it._

He’d go forward, and set things in motion—then return here. No, before here: better to hide everything from the very beginning. He eyed Hel, and she stared guilelessly back. Maybe he already _had_.

“I’ll be right back,” he told her, and then took a deep breath and focused on the Gems. If he was going to do this... he’d need resources.

 

* * *

 

**Two decades ago: May 4 th, 1991**

The laws of reality snapped back around him, bending into a different perspective and rendering the other one near-incomprehensible. Tony didn’t stumble, but that was mostly because he’d landed midair and the jetboots kicked in on autonomic reflex. He did manage to land gracefully, though.

Nanites reformed around him, switching from the armour to a suit more fitting of the times. The ones beneath his skin adjusted as well, giving him a sallow, hung-over look—a minor modification to the eyes, a wildness  and pin-point pupils—he’d gotten up to some really stupid things when he was actually in his twenties.

Phone and power lines buzzed around him, tickling extremis’ awareness, but although it was a jolt at first—so abrupt a change from the silent wastes of Helheim—they were all too rudimentary to be a real distraction. Almost quaint, really. Here humanity was, still riding the first wave of a technological revolution, all of them just barely dreaming of the sort of processing power that he had in the tip of his little finger.

The car-park level he’d landed in was empty. No secret cameras watched obsessively, not in this time, where SHIELD was yet made of shadows and other interests were focused abroad, watching with disbelief as the Soviet Union peacefully collapsed. That would change, soon enough, and eyes would remember to look back home. Before then, he could count on being unobserved as he made some investments. His plan might not be entirely complete yet, still rough around the edges, but everything he could come up with required time and money, and if he wasn’t going back to SHIELD—and he couldn’t, he couldn’t, not before he figured out what Loki might have done—then he needed to take steps to ensure he had an alternate cash flow. His self in this time was currently sleeping off the effects of the really dumb things he’d been doing for the last few days, safe in his Manhattan penthouse; Stane was halfway around the world and wouldn’t expect him—

Tony felt himself freeze in the process of adjusting his cuff links. He’d known, sure, when he’d decided to make this stop—but somehow, _standing_ here was different. All his promises to himself teetered in the presence of that first betrayal. If he’d never gone to the desert—

If he’d never built the suit...

The sharp edges of the Gems, still in his hand, bit into his skin. He was wrinkling his cuff, squeezing his hands into fists too hard. He forced himself to relax, forced his finger to uncurl, and fabric made from nanites smoothed out as though it had never been crushed. But the pain was a reminder—he couldn’t afford to start thinking this way.

Steve had been right all along. He couldn’t play God. Hadn’t he seen what it had come to, the last time?

 _Damn him, anyway._ He couldn’t put any real heat into the thought.

But here he was, going off on his own again. He could excuse it—Loki was undoubtedly waiting and prepared for him to come back, he needed to get all his ducks lined up in a row before he did—but at the end of the day, he was still going off solo, breaking his promise to Steve.

“Shut up, shut up,” Tony muttered aloud. This was ridiculous. He was standing in a smelly parking garage in New York talking to himself, when what he _needed_ to be doing was setting up funds. And trying to do it this way, pretending to be his younger self, was a stupid idea. It presented far too much temptation, and god and the entire public knew that Tony Stark was terrible at resisting temptation. No. He’d do this the less straight-forward way, and if the funds weren’t where he needed them to be in two decades then—well, hell, he’d just rob a bank: extremis made doing so a matter of a moment’s thought.

The ICG engaged around him as his suit dissolved back into armour. He engaged the Silencer before he the repulsors, and his rise into the air was in dead quiet. If he _was_ going to do it this way, in this primitive time, then he needed to be a little closer to the stock exchange: the Twin Towers.

God, how naive they’d all been back then.

 

* * *

 

**One decade ago: September 2 nd, 2003**

Tony kept hold of Dyson’s hand as world became ordinary once more around them, but to her credit, she didn’t wobble too much—military exercise plan paying off, he guessed. When he was sure that she had her balance he stepped back, dropping her hand and giving her some space as she looked around. It also let him sync into the complex’s servers. Somebody had been by while he’d been away, and left one brain-damaged soldier behind. He made a note to remember to do that later.

“Where is this?” she asked, taking in the wide windows (fake; they were screens, but very realistic)—the potted plants (real; apparently they were beneficial to mental health, and god knew after four years down here he was running low on that)—and the industrial-grade computer banks. It was all heavily shielded, and underground to boot—Steve would have been so disappointed—

_Stop thinking about it._

All of time and space his to run through, and still Steve managed to

_stop_

“Your home for the next few years, until we crack this thing—and, after that, it’s yours outright,” Tony shrugged, including the sound of moving clothes to match the image he was wearing. “Whether you want to stay or not at that point will be up to you. Colonel Savin’s in a room just down that hall,” he added helpfully.

Dyson didn’t take the bait. Not love-struck or regretful enough to become stupid, then. Good for her. “How did we get here?”

“I would’ve thought that’d be your first question,” Tony remarked, and then immediately held up his hands as she glared at him. “Good grief, you’re jumpy.”

“You just broke me out of prison by—by teleportation! I think I’m entitled to be jumpy!”

“You agreed to it.”

“You can do all this, why do you even need my help?”

“Well, you know what they say about scientists and specializations,” he muttered. “ _Personality_ , Dr. Dyson. I know what you’ve been studying in your permitted time, trying to fix Colonel Savin. I looked into you very closely. See, I can get the memories copied just fine, but the personality—building one entirely digital, quantum, from the start, that I can do fine, but copying something with neurons? Something changes every time, something I’m missing, and it falls to bits.” He waved his hands in frustration.

She stared at him. “I thought you wanted my help with the tissue growth.”

“I said I needed your help with the details,” Tony said, and took another few steps back for prudence. “Tissue growth I’ve got down.”

“Are you sure about that, or are you working on theory? Because I can tell you that technology’s at least ten years out,” Dyson said flatly, and with utter certainty.

_Funny, she’s about dead on with that one._

He grouped up a bunch of nanites onto his hand instead, pulling the ICG’s cloak away carefully to reveal them as they balled up—a gleaming silver mass that he set on the nearest workbench. “I’m sure.”

Dyson looked between him and the extremis particles—and, oh, she was good: “You got to Hansen.”

“Yup.”

Dyson shook her head. “ULTRA-Tech got funding because extremis was deemed too pie-in-the-sky. They thought it was too far out to be viable this side of 2050. But if you’ve got that working, you _don’t_ need me.” She had her chin lifted—oh, there was pride, there.

“I do need you,” Tony said, “I’ve just told you why I need you. I need you to figure out how to clone—transplant, whatever—a personality whole. It’s not my field. Frankly, I’m a genius, but I _don’t_ have the intuition for this field, I never have. You do. You”—he waved a hand at her—“ _get_ it. I need your help.”

“You have _Hansen_ working for you.”

“I have Hansen working against me, is what I have. Hansen isn’t like you, Doctor. She doesn’t have your morals.” He looked away. “I learned that the hard way.”

“Yeah?” she challenged: jaw set, eyes narrowed, feet planted in combat-ready stance—she’d been slowly shifting into it the entire time. “And how’d that go? This is the last time I’m gonna ask: who _are_ you?”

“Well, not a super-villain,” Tony muttered, and dropped the illusion he’d been wearing.

He was probably going to be stuck here with her for the next few years, after all. Might as well try to get off to a good start.

 

* * *

 

**Eight months ago: Five weeks after the Chitauri Invasion of New York**

“Dr. Dyson, it is an honour to meet you,” Tony said, standing to offer her his hand. He had to stand to the side of the chair, rather than shoving it back, since the chair was bolted to the floor. Prison security left a lot to be desired in the amenities.

The MPs guarding her ignored the gesture; Dyson stared at him suspiciously. Tony shrugged, dropped his hand, and re-took his seat while they let Dyson shuffle to the chair. The MPs ensured the door was shut, and took up positions on either side of it, watching Dyson warily—and him, too.

Not that they really saw him. They saw a middle-aged man in a business suit.

With a thought, Tony cut their communications and set the security cameras to view a suspicious-seeming but completely nonsensical conversation about whales. He set the Silencer to give them a bubble of privacy, just in case Dyson was feeling more patriotic than he’d predicted. Then he brought his hand up, and fired mini-taser darts at both guards from the cloaked gauntlet he was wearing. They fell, twitching—still breathing, he made certain. But thoroughly disabled. He tightened the inner radius of the Silencer, including the guards in the dead zone where they wouldn’t hear anything even if they regained consciousness, and turned his full attention to Dyson.

She wore an expression of disbelief. But, to give her credit, there was nothing hesitant about her as she demanded, “What the hell is this?”

“A jail break, if you want it,” he told her. “Sort of. You’d be in my custody instead.”

“Somehow I doubt that you’re approved by the Army Corrections Command. Give me one reason why I shouldn’t start screaming.”

“I’ll give you two.” He held up two fingers. “One, no one would hear you. Two, I plan to collect Colonel Savin as well. I’m sure you have concerns over how he’s been treated during your stay here—justified concerns. But, you come work for me... I can’t promise you much free time. But whatever you have, you can use it to try to repair the damage he suffered, with unlimited funding and materials. And _I_ won’t do a damn thing to him, except provide room and board.”

Her jaw clenched. “Who the hell are you?”

“Someone who needs your help.”

“What the fuck _for?_ Are you some—” she looked at the guards, faint signs of panic beginning to appear, “—some super-villain?”

Super-villain? Not this month, but soon enough. “No,” he said firmly. “This is a private interest. I’m not interested in your work on enhancements. It’s more your side-work that interests me. The nitty-gritty details,” he explained.

Project ULTRA-tech had been focused on grafting cybernetic enhancements onto—or into—a human body. Unlike so many other failed super-soldier projects before it, they’d been _very_ careful not to leap too quickly to human testing, instead snapping up two smaller projects working on cloning. Under the direction of Lieutenant Dyson—and it was a criminally stupid oversight that she hadn’t been promoted way beyond Lieutenant for her groundbreaking work—the team had advanced cloning techniques to such a point that they could grow incredibly complex systems.

Not as complex as a human being, of course. Nowhere near that complex.

But he didn’t need her help for _that._

“That doesn’t tell me who the fuck you are,” Dyson said. Good catch.

“ _That_ , you’re not going to learn unless you say yes,” Tony said, grimacing. “I want a human clone, Doctor. Of me. No one else. Not one to do experiments on, or harvest organs from—I want a _twin_. An equal.”

She stared at him. “You’ve gotta be kidding.”

“It’s harder than you’d think to find researchers of your quality who are willing to be locked in a secret facility for—eh, five years, let’s say.” Tony shrugged. “Given how much difficulty I’ve encountered working on my own, I don’t expect quick results. But when you’re done, you can keep working in my facilities, and I guarantee a lifetime of unlimited funding for getting Colonel Savin fixed. Or you can take a millionaire’s pension and a new identity and... go anywhere. I don’t care. I just want a twin. Come _on_ , Dyson—work with me, here.”

“You walked in here and downed two USDB guards and are talking treason at me. And you think _I’ll_ think you’d just let me go?”

“Well”—Tony drew out the word slowly—“they certainly won’t.”

“My sentence is fifty years.”

“New York was invaded by aliens last month. It’s a brand new world. Let me put it to you this way—your friend is currently in cold storage. Tomorrow, he won’t be. Super-soldier programs have got real fashionable again, and this time—hoo boy. You haven’t been outside, Dyson. You haven’t seen the panic.” Tony leaned back in his chair, as much as the prison furniture would allow, which wasn’t much. “You have something I want, and I’m _asking_ you for it, because Project ULTRA-Tech was probably the most ethically-run super-soldier project in the last fifty years, and that’s down to you. Your superiors won’t _ask_ , and you won’t like what they order you to do.”

She stared at him, thinking. He didn’t rush her. This was good, really. For all that she was in prison, she’d gotten there through naiveté rather than malevolence, and he needed someone with ethics, someone he could _trust_ this time, damn it. Not that he could trust her, yet—but maybe eventually.

In the security room, the guard-on-duty had paused over their camera for the last minute, baffled by their conversation. Maybe he should have picked a different topic.

“How do you think you’ll get me out of here?” Dyson asked finally. “You just tased two guards. You’ll never be able to smooth that over.”

“On paper, you’re getting transferred to a civilian prison,” Tony said. “The records will be in order, although everybody with a signature on them will swear it’s forged. Unofficially...” he stood, and tucked his left hand into a pocket, picking out the Space Gem by feel. “Take my hand.” He held out his right, as if to shake, again. Technically, he didn’t need her to actually take it—but technically, she hadn’t yet agreed.

She eyed him distrustfully.

“The first time was just a handshake, a greeting,” he placated. “I’m really not interested in trying to get an _unwilling_ scientist to clone me a twin. That’d just end badly.”

“This is going to end badly anyway,” she said, but she did take his hand. “Fine.”

“Bargain struck.” He felt like grinning, but managed to refrain. “Here we go.” He pictured their destination, and let the Gems do the rest.

 

* * *

 

**Five hours ago: 11:31 PM (EST)**

Wrapped in layers of cloaking tech helped by the twin powers of Space and Time, Tony eavesdropped on his own thoughts. Years of research into every fundamental aspect of the brain and its interaction with extremis made it easy to read data off himself without being detected in return, although, admittedly, that was helped along by the hash his past self had made of his own firewalls.

Stupid, stupid, stupid of him to have run the upgrade just like that. He should have held off on it _at least_ until he’d gotten out of Maklu. What had he been thinking, starting it like that? He’d been rushing—and he’d paid the price for it. He hadn’t understood why at the time. It had taken him years to figure that out—years of tweaking, of the Time Gem self-correcting for everything he did, everything he stuck into place to try to trip up Loki. Years of watching everything balance on a knife edge and realizing that no matter how many excuses he told himself, it wasn’t about avoiding Loki’s traps at all, it was just that he’d seen another way and if it required breaking his promise to Steve, so be it—

Christ, he was tired.

Time to make the ends of the circle meet. Tony slipped past— _hah, past_ —his past self’s currently up-turned firewalls with laughable ease; later, he wouldn’t even remember any foreign system interaction. Of course... the system baselines were identical. Sloppy work all around. He’d been a moron.

 _Can’t say you don’t deserve this,_ Tony thought darkly, and made one... key... _tweak._

 

* * *

 

**Three hours ago: 01:40 AM (EST)**

“This,” said Fury, flipping Steve’s hastily-scrawled report closed and tapping the cover with his index finger, “is a fucking mess.”

“Sir.”

“I thought aliens were bad, and now you’re adding in fucking time-travel.” Fury grunted and leaned forward to set his elbows on the desk. He clasped his hands together. “You brought back Stark, Captain—I was ready to sing your praises and let the President pin medals on you—but this?”

Well, there was some silver lining to it if he’d managed to duck a medal ceremony. “The ‘new’ threat’s been there since our Asgardian ally vanished, Director. We just didn’t know about it.”

“And according to this, that threat’s gone. One power to wipe out another. Although having seen power vacuums before, I’m sure we’ll be plenty busy for the next few years.” Fury shook his head. “So. Interstellar politics just got even messier. You’re right, at least we know what happened now. But what you want to do about our _other_ Asgardian problem? Captain, are you out of your goddamn mind?”

“No,” said Steve, “but Tony was. He’s cured of it, but he’s still not well. He needs _help—_ ”

“ _That_ is not my problem here,” barked Fury. Beneath the irritation, he actually looked... offended? “The problem is you trying to play goddamn _politics_ with it!”

“What? _I’m_ not _—_ ”

“You want him to work for SHIELD. _That’s_ a problem.”

Of all the things Steve had expected Fury to say, _that_ hadn’t been one of them. He stared at Fury, arguments deserting him.

“Stark threatened the Council that he’d go public about the nuke,” said Hill, from her position over on the wall. She had a tablet in front of her, and was scrolling through paperwork even as she spoke, but her eyes flicked up to meet Steve’s briefly. “We’d been using that threat to sort out some internal flaws. Two of the Councillors who gave that order have been replaced. The other three might’ve been gone within a year, if we hadn’t been interrupted by Stark’s death and extremis. Instead they still hold a majority on the Council. Worse, China’s now set a precedent for nuking civilian targets in the interests of national preservation of life, and the global response has been a long way from total condemnation.”

“The hysteria over extremis was everything they could have wanted,” said Fury. He sounded disgusted. “So. We have a radicalized Council, and you want to hand them Tony Stark as a prisoner, a Tony Stark who for once is _actually willing_ to build them weapons. You’re right: we need to do something about our Asgardian problem. And if you hadn’t had him broadcast himself to the damn Helicarrier bridge, Captain, it would be a hell of a lot easier to _do_ it without risking the Council gunning for a goddamn global takeover!”

Steve flushed. Okay, so that had been a mistake on his part. “Sir,” he said, staring straight ahead.

“Uh,” said Bruce, speaking up for the first time in an hour—he’d gone cold and quiet while reading over Fury’s shoulder, and eventually wandered over to a corner to tap at a tablet of his own—“Actually. What you’re saying about him being willing to build weapons... are you sure you got that right?”

Steve turned to look at him. “He was pretty explicit about wanting to kill the guy.”

“Yeah, but, considering the record of the phenomena you have there...” Bruce waved two fingers vaguely at the notebook report that Steve had written up, “—weapons, uh, that’s not going to do it. Something to detect, search for the guy in more than three dimensions—that’s going to be more astrophysics than nuclear. We’re talking... portal tech, how to get around whatever ‘wall’ they’ve got up, and something to destabilize copies of the guy across realities. Conventional weaponry wouldn’t—I don’t think you’re getting the limitations of it, here.”

“A weapon you could use to assassinate people from other realities with is _certainly_ something the Council would want,” said Fury.

“Yeah, but I’d bet it’ll work differently on a being that’s ‘connected’ across realities instead of ‘discrete’. Look, I’m not any kind of a weapons engineer, Tony could have other ideas. But I’m pretty experienced with how it works when conventional weaponry goes up against the... unconventional.” One corner of Bruce’s mouth picked up in a crooked smile. “Tony’s seen that. He knows how it goes. He won’t make that mistake.”

“Can we put him into Avengers’ custody?” asked Steve.

“The Avengers have no legal authority to take custody, Captain, except under the auspices of SHIELD.”

“Then US federal custody. Represented by the Avengers. If we can get the President to sign off on it then I’ll take personal responsibility. SHIELD provides space and materials in exchange for access to what he’s working on, but the legal custody is ours.”

Maria paused in tapping at her tablet. “You go that route, you’ll have a hard sell not getting the US military involved.”

“Oh, yeah,” said Bruce. “That’d just be perfect. We’ll be beating them off with a stick.”

“I’ve got a pretty handy shield for that,” said Steve. He looked back at Fury, trying to guess the direction of his thoughts. “Director?”

Fury’s expression was only half-skeptical, which was nearly his default anyway. Steve felt a bloom of hope rise.

Fury leaned back in his chair. “That might be a solution. But you seem to have forgotten how that nuke got in the air last spring. If SHIELD has _physical_ custody, that’ll still give the Council a lot of opportunities.”

“SHIELD facilities have internal cameras. So long as Tony’s on Earth and not stuck down a hole, cut off, he can catch whatever the Council tries.”

“Big Brother 2.0,” said Bruce. Steve shot him a look, but he was staring at the ceiling. “Oh, god, he would, wouldn’t he.”

Fury snorted. “Catch and _stop,_ huh? _Not_ tossing him down a hole opens up a whole other can of worms. There’s no other way to hold him. I’m willing to give the idea that he was mentally compromised a fair shot, and in that case, he may not be responsible for all the actions he’s taken. But until we can clear that he was and that he definitely no longer _is_ , keeping him contained is a responsibility that I have to a higher ideal than just the Council.” He fixed his eye on Steve. “Which should be your first concern as well, Captain.”

“He surrendered to me. If I tell him to he’ll stay put,” said Steve, trying to keep his face as blank as possible.

“This,” Fury held up the notebook containing Steve’s report, “does not provide evidence to back up that claim.”

Of course it didn’t. Steve had glossed over—or flat omitted—anything that might have hinted at the existence of the headband Tripitaka had stuck on Tony; he’d put down stopping Tony from using the Window to Makluan technology being able to disable extremis. He couldn’t tell Fury the truth of it. Tony would never forgive him. Tony would be _right_ to never forgive him.

_Ten million people died in Shenzhen._

Steve planted his hands on Fury’s desk and leaned forward, keeping eye contact. “Stopping another Shenzhen is my biggest concern. It won’t happen again. I—”

 _If Tripitaka hadn’t..._ If a lot of things hadn’t happened... but they had, locked into place when the Window of Time had shattered. Time-travel solved nothing, no matter what Tony thought. But keeping Tony from doing something stupid... was he seriously considering actually using the headband? Even as something to bluff Tony with?

Fury looked almost disappointed, almost gentle. “Your word’s a hell of a thing, Captain, but you’re asking me to trust a lot of lives to your gut feeling.”

Could he—?

He’d halfway done it already, ordering Tony to call SHIELD. If he did this—

Steve looked down at the desk, then up at the others. They were silent, letting him think; Fury didn’t drop his gaze, but Maria was still tapping away on her tablet. Bruce was worrying at the cuffs of his sleeves, fiddling like he did whenever he got nervous. The very first time Steve had seen him do that, he’d been shying away from the guards on the bridge of the Helicarrier. Because Bruce had been considered a threat, too—had fucked up, had made mistakes that resulted in the Hulk, that resulted in deaths...

 _I broke once,_ Tony had said. _I’ll break again._ And in the shadows of his mine-laboratory, he’d looked exhausted.

 _I cannot possibly do that to him. God, what is wrong with me that I’d even consider it?_ Steve’s gut cramped with phantom nausea, the dizzying feeling of stopping only to realize that one step further and he would have fallen into an unseen chasm; he reeled back from it, horrified. _I can’t do that to him. I can’t, and I won’t. I shouldn’t have ever thought of it. I wish I’d never thought of it._

He didn’t know how much of this panic made it easy to meet Fury’s eyes squarely. “I’m not asking you to trust my gut feeling, sir. I’m asking you to trust _me_. If he goes off the rails—I’ll stop him.”

 _God be my witness, I will find another way. Failure isn’t an option, and neither is_ that.

Fury tilted his head, considering—his eye searching Steve’s face, possibly trying to x-ray through to the brain beneath—and, at length, slowly nodded. “Alright, Cap. Looks like you need to go see the President... and we need to dust off Operation: Alexander.”

 

* * *

 

**Now**

Loki’s grin contained too many teeth. It wasn’t nerves or fear, confusing Tony’s senses; extremis let Tony count exactly how many he was showing, and they should _not_ have all fit in that space without seriously stretching out his jaw.

“Subtle,” said Tony.

The grin shifted to a more genuinely amused expression, which of course meant fuck all. “Work for a god and you’re bound to see some wonders.”

“Me working _for you_ would be one all by itself—look, okay, I’m not even gonna try and lie to you, because I think you know damn well how much I hate you.” Tony crossed his arms and leaned back, as much as was possible in the steel chair. “Give it to me.” What _did_ Loki think he had that would convince him?

He preferred his universe’s version of Loki. That one was a lot easier to rattle. Of course, that was a lesser version—a filtered reflection, watered down. This Loki that he was talking to was also a reflection—but Tony didn’t think as much was filtered. There was a mind behind this Loki that was greater than a single reality.

“You’re a pragmatist, Stark.”

Enemy of my enemy. That was _it?_ That was all Loki was going with to try to convince him? Colour him disappointed... and suspicious. “Right, so on the impossible day when Hammer has a bright idea and I agree to work with you, you _know_ I’m going to be waiting for a chance to stab you in the back.”

He’d really appreciate it if Loki would stop smiling. It wasn’t a good look on him, any version of him. “You speak as though that’s not part of the fun.”

If he did this—

_I’m not that fucking crazy_

_shit_

_think_

He had questions to ask, but they were all meaningless. He couldn’t trust the answers; worse, trying to figure out the truth might itself sabotage him. This was Loki’s game, and if Tony played, he wouldn’t win.

And he’d promised to give Steve a chance.

Tony met Loki’s gaze, not quite squarely. He remembered what had happened the last time he’d been tricked into that. “No deal.” He nodded to the door. “You can fuck off, now.”

Loki looked slightly baffled, much as the other one had, when he’d tried to take over Tony’s mind with that alien spear and found the way to his heart blocked by his arc reactor. Good. It was a much better look on him than that grin, or any sort of amusement.

“You think you have a choice?”

“You’re just full of clichés today, aren’t you?” Tony could hear the bravado even as he said it. The thing was—it _wasn’t_ a cliché, the way Loki had asked. It wasn’t a threat. It was like Loki was watching a crazy guy jump off a bridge with nothing but the faith that _gravity did not exist._

And from anyone else, Tony still would have brushed it off, but from _him_ —

Loki grabbed him before Tony had even managed to stand, yanking him forward over the table with limbs that were too long to fit into the space that they did. Tony grabbed the table edge and levered himself upward, all the nanites he’d been harvesting during the conversation coming together to form the most pitiful repulsor he’d ever fired—and Loki pinned his hand to the table with enough force to break bones. He was still too slow—too slow to break the hold before Loki slammed the rest of him down onto the table, too, dislocating his shoulder— _damnit not again_ —and leaving him wheezing for breath around Loki’s hand pressing down on his throat.

Nanites immediately began diverting away from his broken hand, to reform elsewhere, but that was slow. His combat module highlighted pressure points; Tony grabbed Loki’s wrist with his working hand and squeezed in, but of _course_ Asgardians didn’t have the same nerve clusters as humans. Sensors probably could have found weak spots, if he’d had sensors on him, if he’d had the _armour_ —right now he was running almost on basic, senses sharper than human but still too limited to see beneath skin.

Something else slammed into him, then, flattening him to the table. Status reports showed further dislocations and a few strains in the arm he had twisted beneath him. He grunted, trying to move, but it was like the shitty prison clothes had turned to heavy lead plating. Or worse: he’d still have been able to move lead plating.

“So predictable,” said Loki, rolling his eyes—and removing his hand from Tony’s neck, thankfully.

Tony sucked in air. “Back at you,” he gasped.

This time, Loki clamped his hand over Tony’s mouth. “I could silence you with a spell, you know,” he said, smiling wickedly. “But this way I get to entertain fantasies of crushing your head like a melon. Don’t tempt me, Stark—you’re not in a good position right now.”

Most of his neural network and processing power was still physically located in his body. The part of him out on the internet wouldn’t be able to recombine without it, would be... less. Not a consciousness: just a set of instructions. If he died here, he was dead.

On the other hand, if he was going to die here he was going to go down kicking and screaming. Tony bit into Loki’s palm with as much force as he could muster.

Loki growled, ripping his hand away, and to his surprise, Tony tasted blood. He hadn’t been able to mark Loki’s skin scrabbling at it with his fingernails; had he actually broken skin? It couldn’t have done much damage, though. The nanites were beginning to form into a repulsor node beneath his head. He needed just a few more seconds, and his head free, so he could move his head to the side and fire it before Loki saw. A repulsor-blast to the face might disrupt his spell.

“Has even your intelligence deserted you now?” Loki asked incredulously—but he was cradling his hand. “You continue to provoke me when you’ve no hope of winning. It would cost you nothing to hear me out, Stark.”

_Yeah it would_

“Or...” Loki tilted his head curiously. “Have you been damaged?” he murmured, laying one finger alongside Tony’s temple, and tapping—

—fingernail hitting metal with a click—

_no_

“Or something beyond that...”

He couldn’t have seen it.

_no_

Tony had hidden it, reshaped his own flesh around it.

“...can recognize a leash when I see one...”

_no_

Buried it. Made _sure._

_no_

_no_

_no_

“...is truly _ingenious_ work,” said Loki, and panic whited out Tony’s brain. 


	2. Shield and Sword: 1.2

ateHeartr Ambi.erature 22:   
ime: 00:0000_00:00 T  
BPM 12:0 entTemp 

“Tony.”

Something outside of extremis was pinging at him. Human senses, ordinary ones. Were they? It was hard to think, to spare any attention for them. Extremis filled his brain like white noise, throwing garbage at him, barely comprehensible. Something had fritzed? He couldn’t figure it out.

“Tony, come on. Look at me.” Something. Patient. Patience?

 _off_ was a bad idea to think. Something else. _quarantine_ didn’t get through. He needed to think—he should know this, right? Basics. He knew them. Hadn’t he done this before? Boot up. Something safe.

 _set boot min_ he thought, and the command seemed to take, even though the syntax wasn't particularly correct—but extremis, the bits of it that were working, was as flexible as ever. Most of it was working, he was pretty sure. Or it was off. If it had all failed like the garbage he was seeing now, he’d have been dead.

_reboot_

Everything blinked, and all the garbage sensory data disappeared. He thought. What he was getting now made no more sense. Wherever he was, there was a light not-quite-shining at his face; everything else was dark. A solid wall, concrete, pressed up against his back, but he was crouching. Rhodey’s face loomed too near, disembodied. A flashlight. That was the light. Rhodey was wearing a black jumpsuit, and holding the flashlight.

Recollection. Oh. This was a dream. An old dream, not one he’d had in a while, but familiar. He knew how it ended, and it sucked, but it wasn’t real. It explained why he couldn’t think properly—this was a dream.

Rhodey’s face opened up with relief. “Tony? You seeing me now?”

That wasn’t how it went.

“Are you—” Tony stopped himself. His voice was shaking. The rest of him was, too. “Rhodey?”

“Yeah, it’s me,” said Rhodey, some of the relief fading. “Tony?”

Not a dream?

“That was two separate questions, gum-drop,” Tony said, easing himself into a proper sitting position. He had to flail around for balance with his left arm; his right didn’t seem to be working. Of course. Because Loki—Loki—

Extremis was running self-diagnostics, and the most he could get out of it was status and an estimation of time to completion that fluctuated rapidly. The remaining portion of him, all human, started to panic again. He blinked. It took forever.

“Tony, come on, this isn’t a good look on you.” Pressure—Rhodey. Rhodey had grabbed his shoulder, the working one. “I need you to keep it together, man. Focus on me.”

“Rhodey?” Shit. It wasn’t supposed to be a question. “Why are the lights out?” Had he been moved? Was he somewhere else? _Was_ this a dream?

“You turned the power off. And the backups. Uh, you think you can turn it back on again?”

He’d turned the power off? He didn’t remember doing that. Had it been when he’d sent extremis into diagnostic mode? No. It had been dark when he’d done that. Hadn’t it? He shook his head hard, trying to clear it; the violent motion jostled his arm, made him hiss in pain. But at least it was something real, like Rhodey’s hand on his shoulder. He needed to—focus on that. On the problem. “What happened?”

Problem. Problems. Problem one: something had happened that had fucked extremis up with prejudice. Probably Loki’s fault. Problem two: Loki—

— _knew—_

His brain skittered away from it. Not that problem. _Not that_.

Problem three: Thanos was possibly going to eat the multiverse, if Loki wasn’t a lying liar who’d lied.

Figuring out if problem three was actually a problem wasn’t going to happen without a lab containing considerable computing power, and like problems four-through _-N_ , it was going to be a hell of a lot harder without extremis. The diagnostic was still going on its own; until then—

“I need you to tell me that,” Rhodey said, shaking his head. “We couldn’t get into the room until the power was out.”

His brain was waking up. Thoughts were beginning to move at normal speed. Sort of. Enough to make the question annoying. “I know there’re security cameras in here.”

_Oh god did they see what he—_

If he hadn’t had such a grip on Rhodey’s wrist—when had that happened?—he wouldn’t have been able to resist pawing at his head. Searching for the—checking to see if it was visible. If the cameras caught it—

“Yeah, but all we could see was you talking to yourself, until you started getting thrown around by an invisible person.” Rhodey’s grip on his shoulder tightened. “Jesus, Tony. It’s bad enough when you pull this shit as an adult, you’re gonna give me a heart-attack if you keep this up looking like some kid fresh outta MIT—”

“Hey, I was a lot younger than this at MIT.”

“You were a _pain in my neck_ at MIT.”

“Aw, you loved me, jube-jube.”

This... was not useful for solving problem one. But it did make him feel better. Sticking his head in the sand, what a _great_ strategy. Shit.

“I would’ve loved to have the occasional night to study in peace. Some of us actually _did_ need to study, you know,” Rhodey grumbled, and Tony huffed a laugh at him, ducking his head to avoid the light. Not that Rhodey was shining it in his eyes, but he had one hell of a headache. And a pain in the neck. Fuck Loki and his need to grab Tony by the neck, anyway.

“You gonna let me call a medic in now?” Rhodey asked, and Tony hated the way his voice became oh-so-casually careful again.

“ _Let_ you?” Tony asked, and then shook his head. “No, sure. I mean, it’s fine, call ‘em in.” He wished he could see. He wished he could turn the power back on.

Benevolently, at that moment, the lights turned back on, making both of them flinch as their eyes protested the brightness. After a moment, Rhodey let go long enough to stand up and wave at the door. There were people beyond it, waiting—with the light out of his face Tony could see their legs, but the tabletop blocked their faces and upper torsos from his line of sight.

Fending off the SHIELD medics—who wanted him to submit to ridiculous things like spinal immobilization precautions, and drugs—kept him distracted until Fury showed up to loom over them all. As one did. Tony glared up at him; Fury looked back at him impassively. “Nick—ow, Jesus!”

The medic who had just reduced his shoulder looked back at him blandly and squeezed one of his fingertips on his left hand, somehow managing to avoid jostling the broken bones on that hand in the process, which said something for her professionalism even in the face of exasperation. “Can you feel that, sir?”

“ _Yes_.” 

“Stark,” said Fury. “Reconsidering going it alone?”

Rhodey had shuffled around to sit down on Tony's good side, where he was out of the medics’ way. He was close enough that Tony could feel him tense up. “Sir.”

“Splint me and get out,” Tony told the medics. “Please.”

He must have worn them down before, because they obeyed with a minimum of questions. It might have been nice to grab something from one of their bags before they left. Tylenol, maybe. Aspirin. Not that it really mattered. The minor pain in his arm was a small distraction compared to what—

“Stark,” said Fury carefully.

“He’s run rings around you for months,” Tony said, gritting his teeth as he settled his hand in his lap. The sling wasn’t comfortable. He focused on that.

 _Shit_. That wasn’t what he needed to be focusing on. What the hell was he doing?

Fury crouched down, clasping his hands together loosely. “Then help us patch our security. That’s the point of working with a _team_ , Stark. You cover each others’ weak spots.”

Yeah. Or became them.

“And you got a hell of a weak spot, Stark,” Fury added.

Tony quirked an eyebrow.

“He terrifies you.”

A pause. Too long. Tony licked his lips. “And he doesn’t terrify you?” No, of course he wouldn’t. Fury knew shadow-Loki, the one whose missing fruitloops rendered his plans laughably unworkable. Unfunnily lethal, too, of course, but... defeatable. Manageable.

“Of course he does. Fear isn’t the enemy, Stark. It’s not being able to _control_ that fear that will get you killed. I just spent a quarter-hour stuck in an elevator because you panicked and blew the power out, and you think your odds are better if you take him on alone?”

Tony let himself smile, a bit, because. Well. Nick Fury stuck in an elevator. He was surprised Fury hadn’t just glared the elevator into submission. Or ninja’d his way out, climbed down the cabling—hell, maybe he had. But... “He. Did something.” There was something wrong with his brain. Something wrong with extremis, something wrong with his ability to _think_ —Loki had done something.

Fury looked skeptical; anger curled in Tony’s gut. This was the other problem with teams. But Fury backed down. “Maybe he did. Seems like the results are the same.”

“You didn’t see yourself, Tones.” Rhodey. Tony turned and glared at him. Rhodey just stared right back with that awful face of his, no raised eyebrow, no frown, but completely uncompromising anyway. “You were not all there, at all.”

Because when he thought—if Loki—

—didn’t have the mantra, he thought wildly. Wait. It had taken him that long to think of this—shit. Shit. His brain wasn’t working, he—

_He could’ve pulled it from my head. Eye-contact._

He needed to look, needed a mirror. The headband should have been sitting under his skin, where he'd forced it before SHIELD had arrived to pick him and Steve up. Was it visible now, or had Loki figured it out by feel? His fingers twitched with the urge to paw at his head. He couldn’t. Not in front of Fury—Fury saw too much, Tony couldn’t stop him, but he didn’t have to make it even easier for him—goddamnit, he couldn’t think about this. Every time he tried his thoughts skittered out of control and oh god, if he couldn’t think he had nothing.

And if _he_ had nothing—

“It doesn’t matter,” he said. It—didn’t, really. “We’re dead.” It almost felt like a relief to admit it.

“Tones, _breathe,”_ Rhodey ordered him. Right. Hyperventilating. When had that started? Without extremis, he couldn’t check. “Slowly. Come on, in, this is breathing, out, you can do this...”

It had been against the odds that this particular world would survive, anyway. Probability spat out that some worlds would, but there were things like quasars and supernovas and alien warlords out there. Most worlds in the universe didn’t develop life. That theirs had, and that it had survived so long, was a hell of a lot of luck and nothing else. But it was done, and there was nothing left but the denouement. If Loki was just stepping up his game with some fabricated story about Thanos, then—Tony couldn’t hold Loki off anyway. Nothing on Earth could. And if Loki _wasn’t_ lying... so much the worse. Tony had spent time with his mind buried in a Makluan library nexus; he knew damn well how much Thanos terrified beings powerful enough to crush suns.

“If you really think we’re dead anyway, Stark, then you won’t have anything to lose trying,” said Fury.

Except freedom from the crushing weight of _trying_. Fury had always been terrible at pep talks. Probably too pissed off at him.

But he’d promised Steve. Steve, who’d told him to call SHIELD. And Rhodey was sitting beside him in this shitty concrete cell. And—well. Nothing to lose. He’d been here before. Made it out then. Wouldn’t, this time. He had nothing to lose, but the thought of trying made his thoughts fall to pieces.

He still had to. For Steve. Tony breathed out. “Okay.”

They’d find out, in time, that he’d let them down again.

 

* * *

 

The message reached Steve and Hill as they were about to get on the quinjet back from DC—the Presidential Order stowed carefully in Steve’s attaché case, and everything they needed for Operation: Alexander stowed in Hill’s. As soon as they were back outside of the White House itself, and all the scramblers in the building, a click and then a voice came over their earpieces. Steve recognized their pilot immediately. _“Ma’am, we got a Priority Two message waiting for you on channel eleven.”_

“How long ago?” asked Hill, increasing the length of her strides. Priority Two wouldn’t have overridden their meeting with the President, but it was nearly everything _short_ of that.

_“Seventeen minutes, ma’am.”_

Hill didn’t curse. But she did walk faster, until the Secret Service detail following them were forced to give up all pretense of being subtle about it. “I want it as soon as we’re in the air.”

In the quinjet, the pilot passed them over to a secured line with Sitwell on the other end. “Catch me up,” Hill ordered.

_“Deputy Director. We lost contact with the Raft two and a half minutes ago. Flyover showed our people still on the barge, but they signalled a total power loss and to keep quarantine until further notice. The Director was below, ma’am.”_

The Raft. Where SHIELD had taken Tony.

“Understood. Captain Rogers will be arriving in at the Raft two minutes. Hold the Helicarrier at a distance and make sure we have EM barriers up.” She fiddled with her comm again, flicking speaker control over to the jet’s internal channel. “Agent, we need to be at the Raft in two minutes. Punch it.”

_“Yes, ma’am.”_

The pilot enjoyed Hill’s command for all it was worth—it probably wasn’t every day he got to break the sound barrier over the eastern seaboard, even with SHIELD. Hill caught Steve’s eye as the sudden g-forces pushed them both sideways against their restraints, and switched to a private channel; at her hand gesture, he did the same. He didn’t need it to be able to hear her, but unless he wanted to shout, she wouldn’t be able to hear him over the roar of the engines without it.

“Has anyone given you an AED yet?”

Steve blinked. “A defibrillator?”

“Anti-eavesdropping device.” She dug into a pocket, pulled out one of the pen-shaped devices he’d seen Clint and Natasha both use before, and tossed it to him; he caught it and turned it over in his hands. “Keep that one on you. Use it even when you think you don’t have to, unless you’re in a quinjet. The type you’ve got there can interfere with internal and external comms, and it's bad for the planes.”

“Yes, ma’am.”

“Your objective is to verify whether or not there is an extremis outbreak on the Raft. I’ll give you ten minutes to report negative before sending in the Hulk.”

“Will he fit down there?”

“There’s a service elevator.” Hill’s gaze was steely. “If he doesn’t, the other option is the self-destruct. Time to prove you can keep Stark on a leash, Captain.”

He gave her a sharp look. Her expression was perfectly clear, but—there was something about the way she said it. Well, between her and Fury, she was the skeptic—which was saying something, considering Fury. He’d asked Fury to have faith in him. If Hill didn’t believe him...

Steve would just have to prove her wrong. Keep his word, and find another way—fast. _Damn it, Tony._

“You ever had custody of a prisoner beyond a few hours?” asked Hill.

“He’s not a prisoner. Ma’am.”

“You have a signed presidential order saying otherwise, Captain. Decisions become less clear-cut here than they are in the field. That’s not going to change from here out.” Hill gave him a humourless smile—but it wasn’t unsympathetic. “You’ll get used to it.”

“To compromising?” Steve asked sharply. What the hell did she mean by that? Did she really think the War had been that clear-cut? The French Resistance, German spies, hiding in barns while civilians lied about their presence to the Krauts, neighbours selling out neighbours—the Commandos had been hunting men turned into monsters, but Steve had never let any of his team turn into monsters in return. When they’d captured Zola, Steve had wanted to punch the smugness off of his face, wanted to scream at him until he told him where the Skull was, given up what Bucky had sacrificed himself for—but he hadn’t. He’d never thought for a moment that Phillips would do such a thing, either. But modern-day arguments against torture seemed to hinge on its lack of _efficiency_.

“To doubt,” said Hill, her voice just as sharp as Steve’s. Something in her eyes closed off. She busied herself with her tablet.

Maybe he was being unfair. She wasn’t privy to his thoughts; she didn’t know the darkness to which he’d nearly fallen prey.  

The pull of deceleration pushed him against his seat straps again as the pilot cut their speed, dropping below the sound barrier before cloaking, only a few seconds before they were out over the harbour, low near the water. Steve clicked the strap buckles to release himself, and turned his headset back to the jet’s so the pilot could hear him. “Just lower the hatch, I’ll jump.”

He checked the attaché case just to be sure, although considering its durability he’d have a hard time breaking it open even if he took his shield to it. The shield, at least, was a comforting weight on his back, but the paper in the case was his best weapon here... at least for dealing with SHIELD. Dealing with whatever had caused the power loss would take other tactics.

The hatch lowered, and the stink of garbage wafted up; they were maybe twenty feet above the disguised barge that SHIELD used as the Raft’s surface entrance. “Ten minutes,” Hill told him. “Good luck.”  

He nodded once and jumped. The deck of the barge wasn’t the hollow steel that it looked like; he landed soundlessly, and was immediately identified by a woman in maintenance overalls, a high visibility vest, and an M4A1 Carbine. She looked vastly relieved to see him, and not at all like a zombie. “Captain, good to see you. We’ve got emergency power restored, but communications are all still down. This way, sir.”

In the cockpit of the barge was a ladder leading downward to the next deck—an easy defensive choke-point, although if Fury really had intended the Raft to hold a super-zombie, he ought to have realized that one was unlikely to bother with stairs; they’d have just burned through the side of the ship. But then, the ship wasn’t the primary defence. The agent didn’t come with him down the hatch, just waved him on and went back to her post.

Below, the roof stayed claustrophobically low but the hallway widened. The emergency lights overhead were orange, throwing off the colour aspects of everything. Here, the guards were in full black commando gear and stood at rigid attention. Bullet-proof glass walled off control rooms filled with computers, packed with more techs and higher-ranking agents, who were instantly identifiable by their business suits. Bright glowsticks and flashlights were discarded everywhere around the computers. 

Behind the glass, one of the senior agents—Michael Nichols; he’d acted as Clint’s handler several times in the last few months—caught Steve's eye and made a ‘hold up’ gesture, heading for a door. Steve waited impatiently for the security to recognize him and let the door open, and maybe Nichols saw it on his face, because he was speaking as soon as it did, without the usual awkward pause of deferral Steve got from most of the agents. “Captain. Before you go below, you might want to see the security footage.”

“Show me.”

Nichols gestured him over to a computer screen and pressed play. The recording wasn’t up to the quality that Steve was used to from SHIELD—they’d probably avoided going high-end to avoid problems with extremis. Steve wasn’t sure how much good that could do, since they’d lost communications anyway.

The Raft was supposed to be the highest security prison in the world, a class beyond absolutely anywhere else, and specifically shielded against any electronic interference. If Tony had managed to knock the power out even here, then there was no place he could be held, unless SHIELD decided to drill a hole to the Earth’s core and drop him down it.

On screen, Fury left the room, and Tony remained sitting in his chair. He looked slumped and tired, dressed in orange prison scrubs. Dark roots were showing clearly in his hair; he’d not bothered to fix his stupid dye job with extremis while they’d been in Maklu. He didn’t move for a bit—and then he opened his mouth and started talking to thin air. The sound quality wasn’t great, but his words were clear.

Steve felt his heart sink into his stomach as he kept watching. He’d thought—he’d _trusted_ Anthony when he’d said he’d cured Tony’s magically-induced insanity... that was unfair. Maybe this wasn’t related to the curse that had been on Tony. Maybe... maybe Tony’s mind was just—broken.

Then an invisible force picked Tony up and dragged him over the table, broke his arm and slammed him down. It happened so fast that Steve flinched back from the screen; there was an audible _bang_ as Tony hit the tabletop. His was still fighting, taunting the invisible person—Loki, it had to be—and then his face went blank and white. He was still twitching—there was something unseen very effectively holding him down—when the screen went to static and so did the sound. Nichols shut it off.

“That was when everything went down,” said Nichols. “Colonel Rhodes was down there and first through the door, once we got it open; he reported Stark as upright but unresponsive. Shock. Quarantine was initiated per Raft protocol for extremis-enhanced prisoners. We tried rebooting but kept getting shut back down by something called ‘extr.fs’ until Stark started snapping out of it, a couple minutes ago.” 

“I need the hard-copy of that footage,” said Steve, and then, realizing, “Actually, I need all the copies.”

“Sir?”

“On Deputy Hill’s authority,” he half-lied.  

“Captain—”

Steve lowered his voice and leaned in—it was hard to do so without making it an overt threat, but he did his best. “You know the problems we’ve had with our security. That footage needs to be secured, and it needs to be now, because I still have to report that this isn’t an extremis outbreak.”

Nichols’ lips turned into a thin white line, and he nodded, crossing to over to one of the computers and popping out a small, rectangular box—Steve frowned at it. Was that a tape box? Cassette? He’d seen a picture of one, when learning about information technology, but he’d never actually seen one in use before. He’d thought it was completely outdated technology; maybe he’d been wrong. Nichols handed it over, and Steve took it gingerly. The plastic beneath his fingers didn’t feel as sturdy as a thumb-drive. “This is it?”

“All the electronic copies got wiped—we don’t know what the hell he did, it wasn’t an EMP.” Nichols looked frustrated. “That would’ve wiped the tape.”

Steve waved him off when Nichols would have escorted him back to the deck; it wasn’t like it was hard to get lost when there was only one real corridor. He tipped his head back as he hit the radio, all the better to let the eyes-in-the-sky get face and retinal scans for him. “This is Rogers. I can confirm this isn’t an extremis outbreak. I need a secure line to Deputy Hill.”

Hill’s response was immediate. _“If it’s not Stark, than what is it?”_

“It was probably Stark,” Steve admitted. “But not as a hostile act against SHIELD or any SHIELD personnel here.”

She could read between those words easily enough. _“Casualties?”_

“None so far, except maybe Stark. No fatalities. I need to go below to get a better look.” At which point he’d lose radio communication.

_“Thirty minutes.”_

“That’ll do. Rogers out.”   

He turned and went below again, cornering Nichols quickly. “Elevator?”

Nichols nodded down the hall. “Down there. You’re lucky down below’s got manual overrides, or you’d be rappelling down the shaft.”

“Wouldn’t be the first time.”

The elevator looked like a freight-elevator, but it would only have barely fit the Hulk, and it smelled like it had had too many people stuck in it recently. Since it was being manually operated, he got to ride with another agent, who had the control panel of the elevator open and a gadget hooked up to control their descent. “The Director was just ahead of you,” the agent reported, and then, sounding weirdly both awed and gleeful, “Actually, uh, they got stuck in the elevator when the power went out, until Morrison rigged this up, so he might not be in the best mood.”

Steve didn’t doubt that Fury was in a bad mood, but he’d have bet that being stuck in an elevator had little to do with it. Fury had bigger fish to fry. Speaking of—“How does no one notice this, out in the harbour? Even with image cloaks—”

The agent shrugged indifferently. “The cover up top does actual business dealing with garbage. Punishment detail, for fuck-ups. Uh, sir. And the elevator has sonar deflection. A diver would have to swim into the thing to notice it, and no one goes diving out here.”

In that case they should have made the elevator shaft larger, Steve thought.

It took them a minute to reach the bottom, but the hallway the door opened onto wasn't any more spacious. It was all cramped, submarine-sized quarters—fair enough, although they’d somehow avoided having them on the Helicarrier. The Helicarrier, however, wasn’t going to be their base of operations anymore. It wasn’t designed with experimental weapons facilities. Fortunately for his budding claustrophobia, neither was the Raft.

He stepped past more SHIELD guards who were half-hiding in alcoves. The Raft had been designed as a prison for superhumans; it took two guards to manoeuvre open the heavy steel door that led into the main hallway, and Steve could hear the pneumatic hiss of pumps helping them. From the other side, it certainly would have held him back. It might even have held back a superzombie, although not one with magma breath. He doubted it would do a damn thing against the Hulk, but maybe SHIELD had actually learned its lesson, there. On the other hand, until a few hours ago, Steve even hadn’t known this place existed—which pointed to absolutely no lessons learned at all.

“Sir.” The guard motioned him through. He could hear the pumps working again, behind him, as they began to close it—the pumps, and their heavy breathing, and the breathing of the guards beyond them. Forward down the hall, there were more guards and a trio of medics— _Still? Shit_ —standing outside one of the rooms. Other sounds of life whispered through another doorway, leading out of sight. A feeling like sweat prickled between Steve’s shoulder-blades. Carefully, he made himself relax before he accidentally broke the tape cassette.

He _really_ would’ve preferred the Helicarrier.

Steve strode forward. He didn’t need confirmation that Fury was in that room—he could hear him talking, voice low but not low enough that anyone else in the hallway couldn’t hear him if they tried. “—insight into your difficulty with reaching Asgard. She doesn’t have any love lost for him either.”

“I can’t,” Tony replied as Steve entered the cell, and the ragged edge of panic in his voice had Steve reaching back for his shield.

He paused in the act as the three men in the room—Fury, Tony, and Rhodey, thank God—all looked up at him. Fury was leaning casually against the table, which was the type of foreboding stainless steel affair that SHIELD used on prisoners it wanted to intimidate, but Rhodey and Tony were sitting on the floor. They were close enough that Rhodey was half propping Tony up on one side—on the other, Tony’s arm was in a sling. His eyes were childishly wide as he stared up at Steve. Bruises stretched across his lower face and neck. _Twenty minutes... unless they’re more recent, extremis should have healed those._

As the security footage had shown, he was dressed in orange prison scrubs. SHIELD had stripped him, obviously, and in doing so taken away his armour, too. Steve hadn’t told them about that part, but maybe someone had guessed, or maybe it was just standard practice. Had that crippled Tony’s healing factor?

Steve turned back around. Everyone in the hall was watching him.

“Get his clothes,” he said. His voice sounded strange, distant beneath the thunder of his own pulse roaring in his ears. “Bring them here. Now.”

The agents stared at him, then at each other, and then some of them stared at him again—he felt his teeth grind, and one agent broke and scurried off with a muttered, “Yessir.”  

Behind him, Fury said, “This isn’t what you think it is, Captain.”

He turned back. “I know damn well what it is. I saw the footage. Something walked right in here past all your guards.” And they’d taken his damn clothes away. He’d _known_ that they’d take the armour, if he told them what it was, and so for Tony’s sake, because Tony _was_ cooperating, he hadn’t. But they’d stripped him anyway. He’d known they might. So had Tony.

But he’d thought it would be a concession, psychological. He hadn’t expected it to _matter_.

“Loki,” blurted Tony. His voice had gone up in pitch, and it was too loud for the small room. Now it was Steve’s turn to stare, because after all the times they’d dodged away from names, he was saying Loki's now? But Tony laughed, and it was high and _wrong_. “Loki was here—just here, you think it matters if I say his name _now?_ He can break SHIELD’s cloaks, Fury, he could as soon as you stole them from me.” The words were short and too fast—he was working himself up towards hyperventilating.

Given how Loki had walked right in here, they were certainly in trouble—but that was panic, mindless fear. Steve stared at Tony and had no idea what to say. Had he ever seen him this terrified before? Loki had broken Tony’s arm, that was clear but—merciful Christ, what else had Loki done? How long had he had?

“If I have to get you a paper bag to breathe into I’m going to start thinking this really is a flashback,” Rhodey threatened, waving a hand close in front of Tony’s face until Tony huffed a strangled laugh and tipped his head forward, just enough to rest his forehead against Rhodey’s palm.

Steve flicked his gaze over to Fury, who hadn’t missed a damn thing—including the case in Steve’s hand. “I take it your little field trip was productive,” he said.

Steve nodded once and set the attaché case down on the table, beginning the process of unlocking it. He glanced at Tony again. If Loki could just walk in _here_... well, no place was really safe. But he wanted Tony out of here, with his armour, and in the same room as Bruce—or if not Bruce, then at least with room to maneuver. Being stuck down here in this claustrophobic bolt-hole was unacceptable. Maybe Tony _hadn’t_ minded underground bases as much as Steve did, considering how many he’d built, but he probably minded them _now_. “We’re getting out of here.”

“Excuse me?” said Fury. His head tilted slightly—oh. Steve’s eyes flicked to the cameras and back. No secured conference room, here. Fury didn’t want the Council to know he was doing an end-run.

He got the case open and pulled out the file folder on top. “I’ve got written orders here placing him under my custody. Sir. If SHIELD is inclined to assist by providing more _appropriate_ accommodations, then I’m amenable to us remaining within a SHIELD-run facility.”

Fury took the file, reading the first page inside not leisurely, but not with a great deal of haste, either—checking that there hadn’t been anything altered, probably. “SHIELD is not under the jurisdiction of the United States of America, Captain.”

“No. But Tony Stark didn’t surrender to SHIELD. He surrendered to me, personally.” Which was an extremely generous interpretation of the message that Tony had sent—he could see both Tony and Rhodey raising their heads to look at him with identical expressions of incredulity. “This facility is owned by the federal government of the United States, leased to SHIELD, and located within the territorial waters of the United States. If you keep him here you are holding an American National on American soil against his will and against the express wishes of the President of the United States of America.”

“SHIELD has authority to carry out global peacekeeping missions on American soil. Stark is going to be charged with international war crimes—”

“But he hasn’t been,” said Steve. He flattened a palm against the table—better that than a fist.

“Because he was declared legally dead,” said Fury, with some exasperation.

“Dead or alive, he’s an American citizen, and SHIELD’s agreement with Washington covers this pretty damn explicitly.” He looked at Tony. “Do you want to stay here?”

“Uh,” said Tony, and schooled his expression into something that was not quite so _What-the-hell?_ “No?”

“Then we’re leaving,” said Steve. He clicked the case shut. “Director. Do I need to rent an apartment in Manhattan?”

“No,” said Fury. He sounded halfway between frustration and amusement. Had that been enough of a show, then? “Consider yourself welcome at the NYQH’s lower sub-basements, gentlemen.”

New York Headquarters—Fury pronounced it as one syllable, ‘nick’. Steve had only been below-ground there once, but the elevator down had taken an impressively long time to reach its destination, and not for want of speed. Those levels were sunk even further than the Raft, which at least had managed to contain Tony’s black-out to within itself—but beneath the shielding in the NYHQ’s sub-basements, they had a whole separate wire-up for the scientists moved over from Project PEGASUS. It had both workspace and living quarters, a far cry from the Raft's prison accommodations. The NYHQ was enough of a literal hole in the ground to provide protection for the populace, if Tony tried to do something stupid with extremis—but it wasn't a _figurative_ hole in the ground.

Or at least that was how Fury had pitched it to him a few hours ago.

“We’ll take it, sir.” He stepped over and crouched down and get a better look at Tony. Rhodey, up close, continued to shoot him _what-the-hell?_ looks—had he not been briefed? Steve ran through the travel times in his head and supposed that it was possible, if Rhodey had insisted on seeing Tony right away... and in his position that was what Steve would have done.  

Tony’s gaze skittered away from Steve's own. Up close, he looked... not good. He hadn’t been great when Steve had left him, still recovering from what Tripitaka had done to him—but Steve had thought he’d be safe with SHIELD, at least for a few hours. Now there was ugly bruising around his neck, blooming in the shape of a hand, and lighter bruises on his lower face. And the splinted hand, of course.

“You okay to walk out of here?” Steve asked, pitching his voice low and tapping one hand against his ear.

He was honestly surprised when Tony replied aloud, rather than taking the cue. “Yeah. I—” he broke off, and for a moment, managed to look up long enough to meet Steve’s eyes—and then lost it again, swallowing whatever else he had been going to say.

“Okay, then up,” said Rhodey, giving up on telepathic communication and putting an arm around Tony’s back from his good side. “One, two—on your feet,” and Steve stood back to give them room. Tony leaned in toward Rhodey, swaying slightly, and not at all protesting the continued support—not saying anything at all.

The guards outside the cell were too professional to show much emotion, but they weren’t the chameleons that higher-ranking agents were; their faces betrayed their wariness at seeing Tony leave his cell. One in particular had a tight set to her jaw—anger. SHIELD had lost nearly a hundred people over three months of fighting extremis.

They had to all wait for the elevator, of course, and the back of Steve’s neck itched with the knowledge of the guns behind him. He nearly jumped when the elevator door slid open. The agent who’d gone to fetch Tony’s clothes was accompanied by two wearing suits, not combat gear, and looking significantly more pissed off. They obviously hadn’t expected him to be waiting for them, or Tony to be out of his cell. “Ca—”

“Where’s his coat and shoes?” Steve asked. Tony had been wearing a heavy coat and boots—he had to put all the nanites somewhere, after all—but it was clearly missing from the clear plastic bag containing the rest of his clothes.

“Sent to the Helicarrier, they got weird readings,” one of the agents replied after a pause long enough to let Steve know that Fury had probably given them the nod from behind him.

Under other circumstances they might have stopped off at the Helicarrier, but Tony looked half-dead on his feet and wasn’t healing with extremis. They needed to get to the NYHQ, and proper medical attention, ASAP. He’d radio for Tony’s things to be sent along—and get Hill to reclassify them as material for Operation: Alexander if anyone protested. “Fine.” He took the bag of clothes from the agent and started to give them to Tony, then realized that Tony didn’t have a free hand—but Tony pulled away from Rhodey and reached out to grab it anyway. Steve gestured him into the elevator. The three agents, still standing in it, crowded back warily.

It was a squeeze with Fury crowding in as well. Steve put himself near a wall, the better to keep an eye on everyone else, but Tony just kept his head down, clutching his bag. He wished Tony would just _say_ something—out loud, or over the comm where only Steve could hear. What the hell had Loki done? What had he had _time_ to do?

At the top Fury got out first, his black coat sweeping behind him and instantly getting the attention of everyone else on the deck—Steve could see the way that the techs sat up just a bit straighter, even if they didn’t turn from what they were doing. “Nichols, where the hell are my communications?” Fury snapped, and Steve took that as their cue to start walking faster. Some of the agents were staring at Tony with carefully blank faces. Did they know what Loki had done? How many people had seen that tape?

Steve tapped his own radio while Rhodey helped Tony up the main hatch ladder. “This is Rogers. Situation contained and clear. I need immediate pick-up for—” He nearly said ‘med-evac’, considering Tony, but Tony had already been treated by medics, and in the moment he hesitated, an alarmed cry came from up above. _Stupid, Rogers, stupid! I should have gone first, nobody would have tried anything down here with Fury watching—_ he grabbed the rail and launched himself up without bothering to use the ladder.

None too soon—Tony and Rhodey were looking down the gun-barrels of two armed guards. “Weapons down!” Steve demanded, right overtop of Rhodey’s attempt at placating them as he thrust past to stand between them—he had his shield out, now, the tape cassette awkwardly juggled in the same hand he was using to carry the attaché case. “Put them down, now!”

“Sir—”

 _“Captain?”_ asked the comm agent up on the Helicarrier.

“Down!” Steve barked, and the guards reluctantly lowered their weapons. Both looked incredulous, but they backed off, and that was all Steve cared about. He stepped past them out of the cockpit, glancing around to make sure everybody else got the idea, too. Other agents dressed in high-visibility coveralls stared at him.

“Situation contained,” Steve repeated into the radio. “I need that ride, agent.”

The voice he heard in reply wasn’t the Helicarrier’s communications officer. _“Commander Rogers, this is Zulu-Two, we will be at your location in forty-five. Please confirm ready for pickup.”_

If there were any other agents up top, they were being a lot stealthier than the first batch. He couldn’t hear anyone else except for those he could see and those down below. He waved Rhodey and Tony out. “Confirm that, we are ready and waiting.”

“Our ride gonna be here soon?” Rhodey asked quietly, as they came near enough to cluster together.

“Yeah.” He wished he could see more of the sky. If the jet was cloaked, it wouldn’t make a difference, but being stuck in among a bunch of garbage bins made him feel like he was still stuck under-ground, somehow.  Also, it stank to high heaven.

“Good, ‘cause I don’t want to undermine your play here, but I have about fifty million questions you _will_ be answering.”

“Join the queue,” Steve muttered, and glanced again at Tony. Tony had the bag of clothing tucked up under his good arm, and he was no longer leaning on Rhodey, although Rhodey was definitely hovering. But he had his head down like he was staring at the deck plating, and although that was probably a good idea—even if the barge undoubtedly had defences against long-range spying—Steve didn't think it was due to security concerns, not with the way his eyes looked glazed over. That was a thousand-mile stare, and it wasn't good.

The subdued roar of a quinjet’s engines reached his ears at last. _About time._ Steve glanced at Tony again in time to catch the way he flinched when Rhodey put a hand on his arm. Rhodey didn’t miss it either, not by a mile, and he didn’t let go, either. “Ride’s here.”

“Oh,” said Tony, and Steve felt his frown deepen. Either extremis was fully down, or Tony was really out of it. He should have known that before any of them.

Air rippled near the top of one of the bin ladders, like over hot asphalt on a summer day, and a quinjet ramp descended out of nowhere. Rhodey saw the problem as soon as Steve did—he tugged gently at the bag Tony was holding, then more firmly pulled it free. “You need a free hand for this, man. Come on. I’ll take it first.”

“Wait—” Tony protested, hauling himself up the ladder so close on Rhodey’s heels that he nearly got a boot in the face. Steve jumped up behind, hitting the manual hatch closure on the way and catching Tony when he stumbled.

“Where are we going?” Tony asked as the jet began to accelerate again. He didn’t sound particular interested, or even particularly _present,_ for that matter, as Rhodey helped him get strapped in.

“The NYHQ. What’s wrong with extremis?”

He wasn’t expecting the look of panic that got him—Tony wide-eyed and fully aware, not lost in his own head, and tugging away from Rhodey as he seemed to abruptly realize where he was and that Rhodey was trying to get a safety belt across his chest without jostling his injured arm. “I—”

“Hey,” Rhodey said firmly. “You are here, with me, and Captain fucking America to guard your ass. Stop squirming like a two-year-old and let me strap you in so I can strap _me_ in, because quinjet pilots are lunatics.” Which was a little unfair—this one was taking them on a straight course at a practically sedate speed.

“Oh,” said Tony. “No, they just have a healthy appreciation for the aerodynamic capabilities—”

“Aerodynamics like _shit_ , even you couldn’t make a stealth-capable hovercraft _aerodynamic_. If these things weren’t made of mithral they’d rip apart at half the speed of sound.”

“It’s a titanium dura- _ow_ ,” Tony bit off, as Rhodey carefully lifted the sling a few inches. “No, they do, the under-wings are designed so they can skip off pressure differentials, gives amazing performance in bad weather. I’d have hired—” He stopped himself short.

Steve pulled out some headsets from an overhead compartment, then sat down across from them, not bothering to strap himself in; he had a good grip on one of the handlebars, and even at this pace, they’d be at the NYHQ in minutes. “What’s wrong with extremis?”

Tony grimaced. “I’d know sooner if you’d let me get back to it.”

“So it’s out of commission.”

This time, at least, Tony met his eyes squarely. “Pretty much.” He kicked the bag that Rhodey had tossed under the seats. “This stuff might not be, though.”

“Wait a minute,” said Rhodey. He’d finally gotten Tony secured, and was now working on himself. “The—alien broke it? This stuff which is in your _brain?_ ”

“I don’t know,” said Tony. His voice was very small. Evidently he realized that, because he glared at the both of them and it was stronger when he next spoke. “It’s not _broken_ , it’s just a bit... in need of defragmenting. I’m working on it. I _was_ working on it. What was that with Fury?”

“Legal issues. I’m assuming you don’t want to work for the World Security Council.” He paused when Tony flinched, but when Tony didn’t say anything, he went on. “But we still need SHIELD’s support. Tony... they can _help._ The NYHQ has research floors, basements, sub-basements—I’ve seen them. They can help you—you can help them—find this guy and bring him down.”

“Uhm.” Tony sounded vaguely guilty. “Actually, we may have a bigger problem.”

“What?”

“He was there because—so he _said_ ,” Tony clarified hastily, “but he’s a dick and a liar—he said he wanted help.” His eyes were locked on Steve’s, and the fear in them was clear as day. Tony wasn't even trying to hide it. “I said no, obviously, because I’m not a moron. But he said the Living Tribunal lost.”

The Living Tribunal... _lost_?

The sun had gone out in the east, and a _presence_ had come, too great for a mortal mind to comprehend. Steve had looked at the souls of gods, before—but this one had needed no mysterious, magical gem to make him understand that he was nothing, that he was less than a speck of ash blown before the oncoming storm.

_Thanos..._

“He could be lying.”

“Yeah. But. If he’s not.” Tony swallowed. “I need to figure this out, I need to sort extremis out. Okay?”

It took him a moment to realize that Tony was actually asking for permission—and waiting for an answer, not just diving back into coding. _Huh._ Steve would need to think about what that meant, later. For now, there were more immediate answers he wanted... but if something was compromising extremis, it needed to be fixed yesterday. He still hesitated. “We’ll be there in two minutes. Don’t get in too deep.”

Tony nodded once, jerkily, and his eyes glazed over with a speed that was downright unsettling. Steve wished he’d just close his eyes—better that than watching his thousand-yard stare.

“Fifty _million_ questions, Steve,” said Rhodey.

 

* * *

 

itude 200000000000:)00000000000000  
1.31 p  
cmpr ehtaaaaaaa

Trying to sort out the back of his own head was like typing at a keyboard with a badly broken monitor: he could input commands just fine, but he had little more than his best guesses for he was getting back. Extremis was what let him look at the code of his own brain, and right now it wasn’t working on an upper level. Background processes were still going—the system honestly wasn’t all that badly compromised; if it had been, he’d have been twitching on the floor—but whenever he tried to call up something active it spat gibberish at him. It was headache-inducing, and he didn’t dare tap into the overrides he had for pain and fatigue.

After a couple of goes he managed to ram through an error-checking command—he was pretty sure he had, at least. With that running, the system could repair most common errors on its own, but that was just doing a patch job; if there was something complicated that had changed, then that was something he’d have to fix himself. Possibly with an outside computer—which meant he’d have to program something to interface with extremis, first, because there wasn’t a computer on the planet designed to do that without relying on extremis’ ability to connect direct. And a human computer would be slow, lines of text read seconds at a time.

Too slow to deal with Loki.

If he backed himself up from the uncorrupted armour—he’d probably lose a lot of the upgrades he’d been in the middle of; their core programming was based on the stuff he always kept with him. Probably no memories. Maybe if he isolated samples, first—

Tony pressed the heel of his hand against his forehead; his other hand throbbed, an uncomfortably warm pain that was like a whisper in his ear. _Remember this? Remember this?_ _Rememberthisrememberthisrememberthis_

_STOP!_

...

What had he been doing?

“me. me. look at _right now_ hear, Tony ,doyou —”

Rhodey was squeezing his—foot? His arm? There was pain coming from somewhere—Loki had broken his hand. Was his hand connected? He couldn’t tell if his hand was connected. What was—?

“What?” he asked, and it came out slurred.

Drunk? No. He wished.

“self 0000 ? . youWhat” Rhodey asked.

Elev.10349ation  
46.3 incliFFFFFF

The world spun sickeningly. There was no way to tell up and down; both were the same.  He wanted to pass out. Something was wrong with extremis. He couldn’t pass out, he might not wake up—he needed to fix—


	3. Shield and Sword: 1.3

“—non-contagious my fucking ass—”

“Shut your mouth, Agent, or I will shut it for you.” 

“—look, we got another four hours and that’s it. We need weather readings. Or how about you go explain to Foster, huh?” 

“—can’t think they’ve got a serious chance at the World Cup—” 

“—how fucking dare you! How fucking dare you question my loyalty after everything I’ve—” 

Tony woke up, and the feeds were back online: date and time; temperature; EMF; pressure and pressure waves; position, velocity, acceleration, and jerk matrices; particle analyses; system chemical analyses. He went through the list in indexed order and all were functioning within baseline SNR limits. Error logs showed that cascading errors from higher-order, fuzzy-logic decision-making subsystems had overwhelmed the sadly less robust sensory modules, and the degradation had caused a crash and reset until critical errors could be cleared. Scan of root programming had uncovered one foreign program, which had immediately been quarantined before it could activate. Sensor modules were now repaired. Fuzzy-logic modules remained quarantined and off-line. 

The last decision made had been to fix the errors, so he started doing that.

 

* * *

 

The next time he woke up, it was in fits and starts, bits of a system coming online one at a time as they were cleared as operating within acceptable parameters. Some of the modules weren’t operating within acceptable parameters, but couldn’t be repaired; he skipped them, restored others, and suddenly had enough decision-making ability to recognize the actual problems and reclassify the errors that weren’t _errors_ so much as they were the natural result of a biological neural mesh interfacing with high-order fuzzy-logic-based nanites. He restored more of them from quarantine, and the information from sensor networks became relevant beyond  accepted environmental conditions max duration: 3.98E14 —which was a garbage result; environmental conditions wouldn’t stay stable that long—and cued up notifications of  
        object.human {obj_hum_id rhodey; distance 1.2; height 1.2; part_anlys_nitrate 10.095; ... }  
        object.human {obj_hum_id unknown93023103293; distance 3.3; height 1.7 ; part_anlys_nitrate 0.023; ...}   
        object.chair {obj_inanimate_id chair93023103294; distance 1.3; height 0.6 ; part_anlys_nitrate 0.890 ; ... }  
and so on. Then threat analyses kicked in to process those surroundings, with, _thank god_ —so he could belatedly think a moment later—morality programming right behind it.

_Maybe I should re-order those two._

Morality programming included a whole host of fuzzy protocols, turning rhodey into _Rhodey_ and the realization that the various monitors he was hooked up to had just started to pick up signals that he was awake, and one was about to start beeping. He cut it off with a thought, resetting it to show the same pattern it had been tracking before he’d properly woken up.

The armour. Where the hell was his armour? Where the hell was... everything else? There _were_ active signals buzzing around here, so it wasn't the Raft, but they were all short-wave and they cut off only tens of metres, maybe a few hundred, from his current position. Beyond, there was nothing. It was almost like this was a building that somebody had jettisoned into space or sunk into the Marianna Trench, a tiny little world, all that was left of humanity.

A scream rose up in his throat, and Tony choked trying to force it down, finding out in the process that his throat was as dry as sandpaper. How long had he been out? Internal clock said eighty-two days, but time sync logs were corrupted. The ECG, EEG, O2, and numerous other monitors he was hooked up to said it probably wasn't much more than six hours, assuming it hadn't taken him long to get here, wherever 'here' was. If he’d gone through a portal, then both might be correct.

“Hey, Tony, calm down, man, you’re safe—” Rhodey grabbed his hand, and that was familiar, waking up in the hospital in Bagram and not having a goddamn clue where he was except that Rhodey was there and he wasn’t in the desert. “You’re in New York, SHIELD’s headquarters. It’s safe here.”

“What happened?” he rasped out, flinching away as the other occupant in the room came up on his other side. The ID hanging off of the guy’s pocket named him one Shahir Guindi, RN with level 7 medical clearance. That explained why he was in here, then. Why no doctors?

“You collapsed in the quinjet,” said Rhodey. “Scared the bejeezus out of me _again_. You keep doing this you’re gonna have to start paying my life insurance premiums.”

_What happened to_ Earth?

“Can’t, I’m broke,” Tony replied with a tight smile. “How long—?”

“You’ve been out for a little over six hours, Mr. Stark,” said the nurse, Guindi, keeping his hands up, in view, and not moving any closer. “Are you the one who disabled the monitors?”

Six hours. Enough time for the world to end. _But Rhodey’s here_ —and Rhodey wouldn’t be here if the world was ending; he’d be out there, fighting against it to the last.

Monitors. Right.

_Cooperation._

He flicked a thought at them and restored their normal functioning. Half of them started beeping immediately, and he winced, but Guindi reached over, moving with careful slowness, and shut the sound on those ones off. Tony wished he’d shut the rest off, too. They were still electronic noise in his skull, and beyond that they were pointless and annoying. Likewise, the IV in his arm part_anlys: saline which he’d have ripped it out if Rhodey hadn’t still been hanging onto his other hand. Which was not broken anymore; extremis had fixed that hours ago. He reached up with the hand Rhodey wasn't keeping captive and started tearing sticky electrode pads off of his forehead.

“Tony,” Rhodey sighed.

“Mr. Stark, please leave those in place...”

 He ignored them. Extremis gave new meaning to the words ‘self-check’. The knowledge contained in the error logs was already in his brain; it was just a matter of running a subroutine to access it, make it part of his foremost thoughts. There were a lot of errors.

When he’d been hit in Maklu by the alien beam that had deactivated extremis, he hadn’t shut off fully; his biological side hadn’t been affected by that. _This_ had been a system-wide effect. He’d thought he was fully integrated before—as integrated as he was going to get, anyway. _Hah._ He’d _thought_ he understood everything he’d done to himself during his quick trip into the Makluan library nexus. But extremis 2.0 had been compiling and executing while he’d been having his little reality break, so maybe he really just knew fuck all.

_I’m a fucking moron. This isn’t going to be a quick solution._

And meanwhile, there was SHIELD to deal with—and Steve—Rhodey, and Pepper, and everyone he’d tried to let go, because he was back on Earth and fully corporeal... and still too slow to take down Loki. 

Memory usage spiked as processing skyrocketed, logic relays and fuzzy-intelligence networks going haywire trying to compensate, spitting out noise like a heavy metal concert, while on the biological side, a screaming demand for oxygen left him gasping for breath, getting the rapid attention of the eyes watching him, a burst in signals traffic that was too structured to be noise. Audio, and EMF, signals he could track and understand; he scrambled to listen, shutting down loops as fast as he could and feeding himself data that wouldn’t start fucking _cascade errors—_

“—Mr. Stark, good. Breathe out. Okay. Do you know where you are?”

“SHIELD. New York,” he replied with barely one percent of his attention. Aliasing split his vision, until he managed to shove more memory space at the debugger, and it fixed it, spewing out error logs in the process. So. He’d managed to fix the errors in his system, and finish installing the extremis upgrade... but he hadn’t managed to eliminate the _source_ of the errors. Whatever Loki had done to him was still there. A quick check showed him that the foreign program he'd quarantined while in safe-mode was still safely isolated; it hadn't been the source of this attack.

_Shit._

“Good. Keep breathing, just like that.” Guindi’s eyes were in soothing shades ranging from #550000 to #290800; his smile was kind, and very warm for all that it was still professional. Guy liked that his patient had stopped freaking out on him. “Do you know what day it is?”

“That wasn’t—it was a programming error,” Tony blurted, setting the debugger to run automatically, which was risky and memory-consuming, but less risky than going around with errors being generated at the current rate. He considered reprogramming himself to stop shivering while he was at it, but set that idea aside for later, even though it was a pointless reflex now even as a defence against the cold, since he had nanites beneath his skin that could do a much better job. Should do a much better job. He didn't even feel cold, actually. “It’s February 23rd and I’m fine now. Joys of transhumanism.” The thought of being psychoanalyzed by this smiling man made his skin crawl—not a sensation he could easily edit away; this was emerging from somewhere deeper inside his core programming.

Rhodey groaned, but there was nothing except reassurance in the way he squeezed Tony’s hand. “Tony, humour the guy.”

Tony made a face, and humoured Rhodey. Humour was right; he didn’t really _have_ fully autonomic functions anymore. Who was Guindi and why was he being nice? SHIELD doctors were never this nice—was that why there was a nurse instead this time? He turned to the external signals. There was wireless traffic here, but it wasn't connected to anything important. Data lines hummed behind the walls, but they were well-shielded enough to keep him out without more focus than he could currently spare. The camera system wasn’t secured half as well, though, and he snuck in through a system that, like most North American systems, was under-engineered and therefore over-rugged to compensate, permitting a far stronger signal than the system actually needed.

Permissions and authorization settings confirmed the nurse’s name was indeed Shahir Guindi, and he had enough combat badges that if Tony had woken up crazy, he’d probably have been just fine until one of the dozen armed guards outside the door could get in. He ran Tony through a series of standard questions: date, place, time, what happened—and not so standard: how long have you had alien robots in your blood—before launching into increasingly complicated questions, some sort of neurological exam. This was apparently for the benefit of the neurologist and psychiatrist watching the secured feeds, neither of whom were qualified in basic marksmanship, let alone masters of Madhya Kalari. The skin-crawling sensation increased. Tony answered with about a tenth of his attention— _deflect, deflect, deflect_ —and with the rest, such as he could spare from debugging, crawled through the system, trawling the logs and layout.

Footage from the internal security system made its way through his head, and it didn't take him long to find what he wanted.  Steve stood inside an elevator with its doors open, as Tony was wheeled out and down a hall on a gurney. Rhodey followed, but Steve didn’t, looking regretful. “Cutting the line isn’t good enough,” Steve snapped into the elevator’s comm. “You need to reel it up, create a buffer area. You don’t need a damn quarantine, it’s not contagious. We just need shielding to keep him from hacking signals accidentally.”

_“If we do a manual disengage like that, we won’t have_ any _contact below. Captain—”_

“Get Fury or Hill on the line, they’ll approve it.”

He flicked forward through the footage. Steve had left, going back upstairs along with half the scientists. And then... communication was cut off. They were sealed in down here, in the bowels of SHIELD’s New York Headquarters. The NYHQ finally living up to its nick-name and turned into a prison.

_But Rhodey’s_ here—

And Steve wasn’t. No amount of concrete and lead would stop Steve, though. _I need my armour._ Armour wouldn’t stop Steve, either— _he wouldn’t, christ, I don’t have to—I do have to._ “Where are my clothes?” he asked, cutting Guindi off mid-question.

“Left on the quinjet,” Rhodey said, his face set in an expression that was _almost_ like his disapproving ‘ _you were the one who got blind drunk last night;_ you _find your goddamn pants_ ’ look, but there was too much sympathy. Tony didn’t want his fucking pity. “We were all glad you didn’t knock out the East Coast power grid, but it was a _risk_ , Tony.”

He stared down at the blanket bunched in his lap. “I didn’t.”

“Yeah, but—”

“When are they going to run the lines back up?”

Rhodey raised his eyebrows— _ah_. He hadn’t told Tony about the lines being pulled down—thick bundles of fiber and CAT6, now wound round on spools at the bottom of their shafts and shut behind enough walls that he really only knew because of the security logs. Physical distance meant no signal in or out. “When the nice doctors say you’re not in a state of mind to knock power out.”

Two floors up the nice doctors scribbled away about what they saw on the monitors. The known-yet-unknown distance above pressed down, suffocating with its silence. He wanted out, he wanted his armour, he wanted _out_ —

_Cooperation. Cooperate._

His lungs kept drawing in air. His mouth produced answers to Guindi’s questions. He wasn’t really paying attention. He wanted his armour. Rhodey said he’d taken out power on the Raft—he couldn’t remember it, but he _had_ , unless it had been Loki. If he could do it again then they’d know whether or not it really was him. If he could do it again then he could take his armour back and all the boosted sensor suites that it boasted, could have access to a world outside again.

In the Raft his armour had been nearby, not somewhere completely out of reach. But there were reactors down here—arc reactors, large ones, designed to power high-energy research. Given a hard-line to those and time, he could get a signal out to anywhere, he was sure.

But he didn’t have a hard-line and there wasn’t enough time when he wanted the damn armour _now_. If Loki came back—

_STOP_

His vision flickered.

Errors found: 12309

_Shit_.

_I can’t keep doing that._

All his feeble, scrabbling efforts were met with silence. The vacuum outside—the gap—pressed inward, an all-consuming emptiness: uncertainty. If he closed his eyes, did the world go away...? Tony grit his teeth.

Guindi noticed. “We’re nearly halfway through the list,” he said, half-apologetically, half-encouraging. “Thank you for being so patient, Mr. Stark.”

“Great,” said Tony. “How about some positive reinforcement? You gonna give the OK to restore the hardlines after this?”

“After forty-eight hours’ observation.” 

Tony gaped at him. “ _Forty-eight—_ ” Rhodey looked surprised, too, that was—good? Bad?

Guindi’s friendliness grew a spine. “From a public safety point of view you’re infected with an incredibly virulent pathogen, Mr. Stark. Forty-eight hours is a dangerously unsafe _minimum_.”

Forty-eight hours. Forty-eight hours, of the silence ringing in his head and the end of the world come early, the death of everything around him. _in forty-eight hours I can probably rewire it to ping the armour_ but they wouldn’t let him at the reactors, of course... but if he had _forty-fucking-eight_ hours, then he didn’t really need a direct power line from the reactors: he could reprogram the reactors themselves via extremis, and cycle them into a state of carefully controlled instability. All signals, in the end, were just energy in flux.

The other solution, of course, was to go more... subtle. This place was shielded by mass and distance. But all shielding was really just a matter of degree. The sensor suite he had in the armour was far more sensitive than that which was in his skin—just as the processing suite in his personal nanites was far more developed than that in the armour—but with enough focus and time, he could change that. The downside being that it would leave him strung out like a junkie, waiting for a noise from beyond...

Three and a half hours to cycle the reactors up with enough control to stop them from destabilizing, give or take twenty minutes. _christ i hate silence._ When had that happened? He’d never had a problem with it before. Had he? He had to find a quicker way to do this—

“There are a hundred and sixteen people down here and eighty-two researchers, and you haven’t told any of them about the forty-eight hour limit. They’ve only been told a level two containment protocol. ‘Precautionary containment’ and, ‘expected duration of less than eight hours’,” Tony said, reading off of manuals stored on the internal network. Leverage, _christ please..._

“That’s not your problem,” said Guindi, voice firm. “Now, if you could please—”

“No. No, you want me nice and stable, I need access to the goddamn outside world, or I am going to assume you’re all figments of my imagination and _vibrate out of my skin_. Hardwire, _now_.”

“Tony—”

“Mr. Stark—”

“Ah, ah, ah!” Tony rode right over both Rhodey and the nurse’s objections. “Nope.” He tugged hand free of Rhodey’s grip—much too easy to do; extremis had de-aged him and added alien strength to his fingers, and Rhodey had let go, anyway. He flicked the O2 monitor off his finger, pulled the IV, ordered the hole in the blood vessel closed before it could bleed, and ripped the electrode pads away.

“Tony, sit your ass back in that bed before I put you in it.”

Guindi wasn’t moving to try and put him back, despite all of his martial arts degrees. Neither was Rhodey, for that matter. Maybe they were trusting in the door, manually locked and barred from the outside, or maybe they just weren't idiots. Tony scrambled out of the bed—the floor was freezing concrete against his bare feet—and crossed to the door, pressing his hand against the crack. It was steel, which wasn't ideal, but he could work with it. He eyed the machinery in the room as nanites crept from his skin onto the frame. There’d be gold circuitry in the microprocessors.

“Mr. Stark, we _are_ trying to help you,” said Guindi. “You’ve been having dissociative episodes—panic attacks. Those are dangerous for someone with your abilities. You could hurt someone.”

“Haven’t yet.”

“Zombies, Tony,” said Rhodey, and Tony flinched.

“That was different—”

“That’s what we’re trying to guarantee,” said Guindi gently. “If you don’t want to remain sitting or lying down, you’re free to move about, that’s fine. Wherever you’re most comfortable. But we do need a comprehensive baseline interview.”

“Okay,” said Tony. “Okay. We’ll do that—after you restore the hardline. I promise I’ll stay here, be a good boy—”

“Tony, for god’s sake, the zombies were pretty fucking bad! Would it kill you to cooperate for once?”

“I am cooperating. I’ll stay right here. See, you _need_ me to cooperate to do that,” and he pushed at the door, gently, just enough to tip it open—his nanites had eaten through the seal. They should have gone with a blast door, something thicker. Did they think that just because he didn’t have his armour, he’d be helpless against a goddamn _door?_

In the hall beyond, the guards aimed their weapons at the now-ajar door. They’d gone for conventional weapons, SI845s, his own design. A good choice. Conventional in general was a good choice; SHIELD still hadn’t worked out how to build proper energy weapons without chips, controls, regulators—things he could fuck up just by thinking.

One of the agents tapped his radio, without lowering his weapon or letting the barrel waver a millimetre. “Colonel Rhodes, come in, please.” Tony heard it in stereo, through the door and through the signal.

“We’re good here,” said Rhodey, one hand on his own comm. “Tony. This is not helping.”

His heart pounded—adrenaline rush, combat readiness—oxygen demand increased. He didn’t try to dial it back. “You know, after all these years you _really_ oughtta know better than to make it a challenge,” and he thought the ICG on— estimated life (current expenditure): 481.

 _Which makes this a bluff._ He could get out of here with the ICG. He might or might not be able to do it in eight minutes.

Bare feet meant that the steps he took back further into the room were silent; he turned on the speaker system for the room and pointed out, _“See, you actually do need me to cooperate.”_

“Tony—”

_“Yeah, that would be me.”_

“This is not MIT,” said Rhodey, carefully—angry. Controlled. His voice was dead level, and Tony hated it. _shit get yourself under fucking control stark_ “People have died. People could continue to die from extremis—you know you make mistakes when you get tired. People will die if you knock out the power to New York.”

Tony decloaked—a sudden enough re-appearance to make both Rhodey and the nurse step back—and if he’d had any doubts about Guindi’s combat qualifications, those went away on witnessing what the guy did with his startle reflex. _wonder why he went into nursing_ “Yeah, but I’m cooperating.”

“Didn’t seem like knocking out the Raft was something you meant to do, Tony,” said Rhodey, still oh-so-careful. _advantage of being known for having a highly infectious disease_

“No, but I didn’t mean to get locked in a shielded room without my armour and _with_ an Asgardian who has a thing for choking me out,” he volleyed back. “And here we are and this is really stupid, Rhodey, I just want a goddamn signal in, I’m not asking for a terabyte line, I just want goddamn proof this isn’t a fucking cell in the middle of nowhere—” _nowhere_ came out _Ginnungagap_ —“‘cause look I’m freaking out you want to psychoanalyze me here it is and I haven’t done a goddamn thing to the goddamn power—”

 Rhodey—sneaky, sneaky—had been inching his way closer. Tony was suddenly aware that Rhodey was close enough to reach out and touch him—had, in fact, reached out and put his hands on Tony’s upper arms, was sort of working his way around to a hug like somebody might creep up on a very skittish cat. It was slightly insulting, and Tony might have objected, except that the errors overflowed the debugger and dizziness had him stumbling—forward, his head onto Rhodey’s shoulder, because even with three extra inches Rhodey still had him beat. At least when he was wearing boots and Tony was barefoot.

Tony breathed in. Rhodey’s uniform smelled like laundry detergent, not like sweat and sand and dust. Clean. Sterile. He shunted more space to the debugger and the world steadied beneath his feet... and pixellated a bit more. “I need a line. I just need a line out—I know people died—I _know_ , it was my fault, please, I just want to make sure they’re not—all gone—”

Rhodey was also talking, he realized, as the debugger cleared out the garbage noise in his audio processes that had translated to turn all sound into a dull roar. “You’re okay, man. There’s a whole world out there.”

“It’s silent in my _head_ ,” Tony gritted out. “Rhodey—I’m cooperating—”

Christ, if only he could move—sit back—something. Something that wasn’t _begging_ , pleading like it had ever made a difference. Every instinct in him except one was screaming to stop putting himself in this terribly vulnerable position. And yet—

“Give him the line,” said one of the psychiatrists—watching Tony watching him, but only one part of the loop knew that it existed. “He’s panicking but he’s keeping it together.” _point for you_ But then, that was... Leonard Samson—Steve’s psych, the one Steve actually liked. Had to be decent, then.

“And the ‘infectious disease’ part?” the other doctor asked, Sahara-dry.

“Oh, come off it, you just want samples.” Samson sounded testy. “Just ask nicely.”

“Easy enough for you to excuse a body count.”

Samson laughed, an ugly, booming noise. “Johann, you’re working for SHIELD. Better get that stick out of your ass. Infection time on extremis is under half an hour, we’re more than past that. Consider that an override from psych if it makes you happy—he’s right, he’s cooperating. He gets a carrot.”

Orders were sent, in person, face-to-face: Tony watched through the cameras. Doors unsealed. He leapt through each one at the speed of thought, alien nanites letting him _spread_ past where any human technology would be expected to maintain contact. He didn’t really need the hardlines completely connected. He just needed them to get near enough that he could piggyback them most of the way through the NYHQ's shielding—but even if they remained out, the thought of a connection, the mirror of the thing itself... that was poetry. This was science, limited by physical distance.

Guindi had started asking questions again—tedious questions, that could be answered with one word or left more open-ended; questions designed to draw out, to reveal thoughts. Tony let him, and let Rhodey lead him back to the bed, let himself be hooked up to alarms—let his _body_ be hooked up to alarms; his self waited, poised, as the last lead blast barrier was rolled back. Satellite data—

“—up forty-three points so far today, riding a wave of optimism as reports continue to roll out of China, all with the same message: the Nanoplague is—”

“—important that in these times, we do thank God, in all His glory. But we must do more than that, too. Our brothers and sisters in China will be suffering the after-effects for a long time to come, and will need our help—”

“—speaking from Beijing, publicly condemned SHIELD for refusing to release any further details. Steve Rogers, aka Captain America, has been speaking to an American Special Committee in a lengthy session that started over four hours ago—”

and one of the sergeants tugged on the cord they’d so hastily rigged up—cord to pull down, and on the other end leadlines pulled cable back _up_ to top-side. Closer... and data _flew._

“—relief efforts increase—”

“—looking grim—” 

“—on Capitol Hill this morning—”

“—satellite array—” 

Signals burned like fire, like beacons. A trillion indications of _life_ , the universe, everything—they _existed._ Tony let his mind spread—found his armour, scanned it, tweaked it, scanned again—revelled in the data. Audio, video—look, there was Steve, arriving to testify this morning... absolutely surrounded by news crews. Somebody had leaked something.

“...Tony...  eyes are glowing...”

Rhodey’s voice sounded like it was coming from a long way away. He let himself ignore it. The internet spread out before him, and it would be so _easy_ to get lost. Drift away. Until something pulled him back.

On the clip playing over again from this morning— _CAPTAIN AMERICA ARRIVES ON CAPITOL HILL TO TESTIFY ABOUT NANOVIRUS CURE; SUPERVILLAINY INVOLVED?—_ Steve looked just thrilled.

 

* * *

 

“I’m sorry, ma’am, but under the Charter signed by the founding member countries, and my own contract with SHIELD—”

“Is there a damn thing you _can_ tell us?” one of the other senators wondered. Cameras flashed, capturing the disgusted expression on his face.

“—I am prohibited from revealing that information,” Steve finished doggedly.

“Thank you, Captain Rogers, I believe we all understand the source of your inability to speak,” the chairwoman said dryly. Her eyes, sharp and flinty, bored into him for a long moment, and then she looked down to flip back through her papers.

Steve wondered if that meant this circus was going to end soon. Him testifying was something that needed to happen: people were scared. There had been riots in Paris this morning, over the Nanoplague _stopping_. A few other cities had teetered on the brink. After three months of extremis, people needed the re-assurance. There was a lot that Steve couldn’t tell them, but he could tell them that extremis was neutralized, and it was better that he do it now, while Tony was still unconscious and Rhodey was around to guard him from himself, SHIELD, and Loki alike. Despite knowing all that, he still felt like he was going stir-crazy before the eyes of these senators and half of America.

After the Chitauri, he’d been shielded from having to do this by both secrecy and SHIELD itself. This time, he was lucky that he had Natasha along for the ride. Most people didn’t realize how good his peripheral vision was; she was sitting beside him and he rarely looked at her, but through the twitches in her expression she kept pointing out which questions he should refuse. They’d probably have directed questions to her, too, except that she was wearing some sort of mask that gave her a different face—apparently, the latest in SHIELD holographics. It didn’t have anything on Tony’s ICG, but it let Natasha sink into anonymity as Steve’s ‘lawyer’.

 “Senator Whitmore...”

“Thank you, Madam Chairwoman. Going back several months to the beginning of the outbreak...” said Whitmore, and Steve resisted the urge to groan. They’d already been ‘back to the beginning’ several times. He was probably going to have nightmares about Tony’s headless body tonight, tomorrow night, whenever he next tried to sleep. Half the senators were clearly convinced that something had been found in the Tower and that SHIELD was hushing it up. “I understand that on November 25th of last year, you were reported as MIA, Captain.”

Whitmore waited for him to answer, so he leaned forward to speak into the mic. “Correct, sir.”

“And that, pending your return—recovery?—on December 11th, you were placed on leave pending psychiatric evaluation—” The rest of Whitmore’s words were swallowed up in a roar as the room exploded; the murmurs of the backbench turning suddenly into shouts and speculation. Natasha, beside him, made a furious sound and scribbled on her legal pad— _HIPAA, he can’t say publicly—shut down now?_

Steve shook his head at her. It was actually funny, a bit—a lot of the reporters looked... outraged. Like it was slander. He’d been sent through psychiatric evaluation right out of the ice, too, and kept seeing Leo weekly—would that outrage these reporters just as much? When the people he cared about had thought he was crazy, that had been infuriating. Now Tony was back, and his entire team _knew_ Tony was back... and, God. Tony was alive.

It took a couple of minutes for the officers in the room to restore order. When it had quieted again—a couple of the press crew had gotten kicked out—Steve said, “I don’t think you actually asked a question there, sir.”

“After returning from ten days MIA and two weeks’ leave” —the noise picked up again; reporters were noting that Whitmore hadn’t repeated the ‘psychiatric’ part—“you returned to active duty, primarily running missions into Nanovirus red-zones for SHIELD, correct?”

“Yes, sir.”

“As you had been before?”

Shenzhen had been a disaster from start to finish. The red-zone classification had been applied retroactively, but it definitely applied. “Yes, sir.”

“The details of which are entirely classified, unlike your later missions gathering extremis samples.” Whitmore held up a file, the cover page of which was more black than white—somebody had gone through it with a black marker and a vengeance. “As classified as this so-called ‘new’ cure for extremis is.”

Steve exchanged glances with Natasha. The murmur of the press gained additional tension. They hadn’t guessed where this was going yet—or maybe some of them had—but they could feel the build before the revelation... damn grandstanding politicians, all of ‘em.

“Senator Whitmore, dramatic pauses do _not_ turn your statements into questions,” said the chairwoman.

“My apologies, Madam Chairwoman—Captain, after you were infected with extremis, why didn’t SHIELD make the data available to other agencies and governments? It’s taken SHIELD _three months_ to synthesize a cure, when if they had cooperated with the WHO—”

“Senator!”

“Apologies, Madam Chairwoman—Captain, can you deny that you were infected with extremis?”

The noise rose again, though not to the level of before: the remaining reporters didn’t want to join their fellows out in the cold. Natasha’s hand was palm down against the tabletop: _deny it_. Of course, he’d sworn on a Holy Bible to tell the truth insofar as he was permitted, before God and the flag of his country. He could _refuse_ , as he’d refused other questions, but that would be answering. So: he could perjure himself, or tell the truth.

If he hesitated that was also an answer. Hell, by not looking surprised that was probably an answer—he pulled the mic down toward him a bit just to have one more moment to think. Truth or lie... he was a terrible liar. The people deserved the truth. People generally did. But was Whitmore really interested in truth?

Didn’t mean he couldn’t use the opportunity to tell some.

“Senator,” he said, slowly, “Since ‘42 I’ve often wished that the formula for the super soldier serum wasn’t lost. I’m aware of how lucky I am. It’s a cold day today—before the serum, I wouldn’t have been able to breathe outside without wheezing. Today I could run a mile a minute and barely break a sweat. There’s people out there in this world, _today_ , who have it a hell of a lot worse than I ever did—whose bodies fight against them more than mine fought me. Science and society have made a lot of progress, but there’s a long ways to go. I wish Erskine’s formula could be a panacea. I wish it hadn’t been lost, I wish to God Erskine hadn’t been assassinated—not the least because Erskine himself was a good man, more than just a great scientist. He deserved to see the end of the War and beyond.”

“Captain, if you could please answer—”

He held up a hand. “I’m answering, Senator. The other reason I wish that the formula had survived was because it might have stopped people—many fellow Americans—from going to some frankly despicable depths in their efforts since to re-create it. In retrospect the medical ethics of the ‘40s seem horrific these days, but at least I knew what I was risking when I climbed in that machine. I’ve read the files from the ‘60s, the ‘70s and ‘80s, and there were plenty of boys who had no clue—who were lied to, who were _used_ , who were coerced. They went in and they came out dead or monsters.

“A lot of people have tried. But even those experiments that were just ethically _dubious_ , rather than outright reprehensible, have been failures. They’ve ruined lives. There hasn’t been one damn success since Erskine died.

“You’re asking me one question, Senator, but I think you’re actually interested in the answer to another one. So I’ll tell you. What I said four hours ago, three hours, ago, a half-hour ago is true. The cure for extremis implemented last night has absolutely nothing to do with Erskine’s super soldier serum or its formula.”

Natasha put a hand on his forearm in warning. Partly she was just playing the lawyer, but part of it was real warning. He twitched her off. In his pocket, his phone buzzed, and he ignored that, too.

“Exactly how the cure works, I couldn’t tell you—cracking it stumped some of the greatest scientific minds on Earth for months. But I thank God that it had nothing to do with the serum, because I know that there are three studies up for federal approval and two more undergoing reviews by military boards this year—I know, because I was asked to provide assistance with all of them. After reading their methods, I refused. I’ll happily assist any study that could honestly pass an ethics review board. I haven’t seen one yet.” He paused—and, hell, couldn’t bite his tongue—“Does that answer your question, Senator?”

Disorder erupted again—intrigued, this time; the audience was wondering what was going on behind those words. _One too many damn politicians, that’s what._ Whitmore had that same look about him.

“No, it doesn't, Captain,” said Whitmore. He’d gone red, but remained dogged. Damn. _Should’ve just called him an opportunist to his face, Rogers._ “Were you infected with extremis?”

Steve looked back at him, and said, very deliberately, “Yes.”

It felt like every camera in the audience went off at once—perfectly timed to capture the triumphant light in Whitmore’s eyes. “Did SHIELD produce a cure, or was that the serum, Captain?”

Natasha gripped his forearm, hard enough to nearly hurt; Steve looked over, deliberately, not quite raising an eyebrow at her, and she flashed the screen of her phone at him. It was a text from a number that Steve recognized as Hill’s. _hardlines reconnected. Looks OK observation continues_

He put his hand over the mic and leaned over to talk to her. “Can we get out of here?”

“Closing the barn door,” she muttered, but nodded.  

Steve stood and pitched his voice so that the senators could hear him without the mic pickup. “Senator, I’ve repeatedly told you that the cure for extremis had nothing to do with the serum. Either believe me or have the decency to call me a liar directly. Now, you’ll excuse me—we’ve been here for hours. I’ve told you everything I can about the cure for extremis. If you want more, you’re going to have to go to SHIELD, or at least to someone with a science degree. Madam Chairwoman—good day.”

“Captain Rogers, you have an obligation to the people of _this_ country!” Whitmore called, but Steve turned and shoved past—Natasha, Natalie Rushman, followed in his wake, snapping at reporters, “No comment,” again and again.

Steve kept quiet. More than anything else he wanted to tap the ever-present comm in his ear and ask, _Tony?_ —but of course he couldn’t, not when he had microphones pressed up beneath his nose. He waved them aside impatiently, edging through the crowd—he couldn’t just bull through them, he’d knock someone over doing that—until they reached the doors, which swung open before them, spilling the crowd  of reporters into the hall outside. There were even more reporters out there. More cops, too. Natasha got a grip on his arm and pulled him along the hallway, not to the entrance, and they both quickened their strides, shedding reporters to cops as they went until they could duck into a stairwell. Steve saw a cop moving to stand in front of the door as it swung shut, and felt a surge of gratitude.

“Ride’s on the roof,” said Natasha.

He nodded and took the stairs four at a time, which was slower than he had to, but Natasha was wearing a business suit. She flicked off the imager as they went, resettling her heavy purse on her shoulder—it was the purse that had the massive batteries the thing required in lieu of an arc reactor.

“Tony?” he murmured, without turning his comm’s pickup mic on. He heard Natasha pull in a breath behind him. She’d let him hear that, let him know that she had heard. Well, he’d meant her to hear. Downplaying what Tony could do—from the rest of the team, at least—was both pointless and dangerous.

But if Tony was listening, he didn’t answer.

 

* * *

 

Enough brainpower to calculate routes to realities on the other side of the cluster, and Tony couldn’t figure out what to say.

At least not to Steve. But Steve had asked him to tell the truth. Guindi just kept asking questions, and they were probing questions, good questions—a more thorough dip into SHIELD’s files showed that he was a class five interrogator—but he was obviously going easy on Tony: quantity over quality, and the lies or the craziness would show up in the small spaces, the inconsistencies. Tony answered him because it didn’t matter if it didn’t add up; they expected him to be crazy anyway. He played along, and played sane, until Rhodey relaxed enough to go argue with the Air Force, and then he kept playing because so long as he was waiting on Steve to show up he couldn’t quite figure out what else to do.

_Cooperate._

When the quinjet finally touched down, Tony switched his attention from eavesdropping on Rhodey to the cameras showing the base commander waylaying Steve and Natasha—they’d re-linked the hard-lines but the lower levels, apparently, were still on physical quarantine and due to be for the next three days, which was one of the things Rhodey was hashing out with the Air Force. Steve planted his feet, hands not quite on hips, but chin raised, not going to be moved, and agents cleared out around them. Natasha melted in among them and made her way to the security room, booted out the baby agent and the not-so-baby agent on duty there, and started to flick her way through the cameras now uplinked with the second set of surveillance on the lower levels—completely independent of the first set, which was all closed-circuit.

As he watched, Natasha turned and waved at the security camera behind her.

He tapped her comm, creating a private chatlink, avoiding any channels that SHIELD’s techs would recognize as being, well, a channel. _“Black Widow. Did I do something to give myself away, or was that just a lucky guess?”_

She raised an eyebrow at the camera, leaning back in the security chair and crossing one leg over the other. _“I cried at your funeral, Tony. I think you can still call me Natasha.”_

His funeral. That... god, that was a weird thought.

 _“Or I would have, if I’d attended.”_ She shrugged. There was something in her expression that looked genuinely pained. _“I had to go hunt down a leak. But you can call me Natasha anyway.”_

_“What’s Steve’s... plan, here?”_

_“You wouldn’t have been safe with SHIELD. So he got himself a Presidential order for custody of you—him and us, the rest of the Avengers—Bruce, myself, Clint, Rhodey for now but there’s rumblings that the Air Force wants him back.”_

So Steve was his parole officer. _“He wanted me to work with SHIELD.”_ No, that wasn’t right. There was some sort of glitch in his thinking, more errors of the type he’d had to ignore to get his brain back online. Everything since Tripitaka—

Tripitaka—

He couldn’t—he—Steve was— _Loki_ —no. He had to... think. The _stop_ command was—but if he used it—no. Needed to go over the programming, first. Clash check. Figure it out.

_Think._

He took a shuddery breath.

“Mr. Stark?” Guindi asked him.

He’d broken off in the middle of an answer involving Isaac Asimov—testing long-term recall? Had they customized this test for him?—he shook his head and delegated Guindi about three percent more attention. “Liked, yes, but he was never my favourite author—”

_“That’s not—that’s not a plan. I don’t know what...”_

_“Whatever you had in mind to take Rudolph out? Share it. SHIELD wants him taken out, too. SHIELD will support you—_ we’ll _support you. Come on, Tony... I thought last year taught you something about the value of having friends.”_

It was such obvious bait. But he hadn’t paid his dues— _“It taught me I’m hard on friends. You might’ve noticed.”_

She paused. _“Pepper could come back.”_

_“If I—what, if I help you do this? I—”_

_“Not just for this. For the fix to extremis.”_

_“And you think that makes anything better?”_

_“Yes.”_ She was very deliberate. _“I do.”_

Freedom from a life on the run. Nothing could be like it had been... but that didn’t mean that it couldn’t be an improvement. _Okay, fair deal. “What’s the catch?”_

 _“I like Pepper.”_ What, really? _“Don’t say yes if you’re going to screw her over again.”_

Best behaviour, then. The same stick that applied if he went and found Pepper himself. Satellites spun above him, eyes in the sky he could look through at will, pinpoint anyone on the surface of the Earth... no. Better to ask someone else instead, give her some space. Not SHIELD, but—SHIELD had nearly lost Pepper; Natasha and Clint had gotten her out in one piece. Ask Natasha—but that would be admitting what he wanted, what he valued, and even if Natasha was telling the truth about liking Pepper, that didn’t mean she didn’t have other motives at the time.

He was over-thinking this. Too many possibilities, not enough evidence for any of them. He could rate them by probability but when they each had _P_ <0.4 that wasn’t much help. Except that he was pretty sure she did actually like Pepper.

Pepper was an easy person to love.

With this method of communication, it was easy to not let the words come out as soft as they sounded in the processors wired to his brain. _“Do it, then.”_

 _“Play nice with the nurse, Tony. We’ll be down soon enough. Say hi to Steve, will you? He’s worried.”_ Her voice, unlike his, _was_ soft. If he didn’t try to read too much into it, she sounded relieved, but still worried.

 _Try_ , Steve had told him.

 _“Hey,”_ he told Steve, tapping into his comm in the same way he had Natasha’s. On the camera Steve turned away sharply from the base commander, waving her off—on another camera, he watched Natasha watching the same. _“Can I have my armour back?”_

_Right, that didn’t sound whiny_ at all _._

_“Yes,”_ said Steve, _thank god._ And what would he have done if the answer had been ‘no’? _“You okay? Where is it?”_

 _“Storage locker A27, one floor down from you, light security.”_ A27 was for mild biohazards, like most clothes would be, which meant it was nowhere near enough to contain extremis in either solid or aerosolized mode. Somebody was going to be scrubbing toilets on the Raft for that.

From the twitch in Steve’s lips, apparently he realized that, too—or maybe he just took objection to storing it under ‘light’ security. How was Tony supposed to know? Steve had stuck him down here. _“Right. Commander—”_ Steve turned back.

Persistent arguing by Steve, however, only got the quarantine decreased instead of eliminated—down to twelve hours, which was better, but left Steve fuming. Watching him made phantom pain echo through Tony’s skull, until he stopped looking. It also got his armour stuck in a lab, rather than given back to him, although it was hardly shielded enough... he wrote programming to call it to his last known location if his link to it got cut off again, although that was a long shot—without the arc reactor to power it, chances were slim the armour would make it through whatever barriers SHIELD put up. _Cooperation, right._

 _“I’m sorry,”_ said Steve for the umpteenth time. _“If I’d known—”_ he cut himself off, there.

 _“You’d have done the same thing,”_ Tony finished for him. _“No blackouts for Brooklyn, I get it, it’s”_ —he couldn’t quite make himself say ‘fine’— _“not your fault.”_

_“It’s been hours already, it won’t be much longer. As soon as it’s up, you can have the armour back. Can you fix extremis in the meantime?”_

_“Uh-huh. Been working on it. Hey, Natasha’s looking for you,”_ Tony told him, and cut the connection.

He returned to the problem of debugging. The debugger was still finding way too many errors; they multiplied so fast that balancing clearing them and hunting for the source was becoming an art form.

Rhodey finally got off the phone with the Air Force and returned yawning, then promptly crashed out in the chair he’d been sitting in before—asleep within minutes. This might have clued Guindi into how long he’d been asking questions for, because he wrapped it up then.

“Rest, eat, hydrate,” Guindi told him, handing over a water bottle and a power bar. “I have no idea what that virus is doing to you, you’ll have to wait on the experts for that.”

“Hi.”

Guindi had shrugged. “Not my call, Mr. Stark. Fight it out with them. But you _have_ been through a massive physiological and psychological shock recently. Give yourself the chance to recover. Sleep. At least keep the monitors on, please.” He left, shutting off the lights at Tony’s nod.

Humans couldn’t produce real darkness as far as Tony was concerned, not after this last upgrade. Even without the armour, his vision had been widened too much. Infrared cast the room in perpetual light. The equipment pinged at him. The data pathways out to the world practically sang.

Tony gave in and curled up on his side, listening to his own breathing and Rhodey’s, beside him. The bed was pretty comfortable, probably because it wasn’t actually a hospital cot. But he’d just _been_ unconscious. What he needed was a second system he could use to take a good long look at his code, and figure out what the hell was up with it, and if his forced down-time had actually fixed all of it.

Or he could do it in his head. _Sure, that’s not a terrible idea._

Start with the obvious first: rule out outside problems. He’d quarantined a foreign file; now he opened up a partition and dumped the file into it, for examination at a second remove, where it couldn’t execute.

Dots and lines added up into something alien, and he had only a moment to recognize _oh shit—_

“You goddamned _son of a bitch_ ,” he snarled, bolting upright in bed. Armour. Armour, he needed—security feeds were on and showing—

“I feel like we’ve had this conversation before,” said Loki.

—nothing; Rhodey was still conked out in the chair, and for all the cameras could tell Tony was asleep, too. There was no one else in the room. This was all in his head.

_SHIT!_

The program. Where was the fucking program, what was it doing to him? He wrote script faster than the human eye could see, throwing up firewalls and— _there_ , it was sensory. Oh, thank fucking christ, Loki was in his head but not in his thoughts, if only he could keep him _out_ of his thoughts. No wonder everything had fucked up starting at his sensor suites: _this_ had been hiding there while he’d been trying to re-write his brain. _Fuck._

For the moral advantage, he threw back the covers and stalked over to the door—well, it started out as a stalk; it turned into something of a sidle, as he couldn’t stand the chance of turning his back on Loki even if it was all in his head, fake data generated by the virus. The door opened easily, and beyond it lay a great, familiar nothingness. He blinked at it hazily. Most of his attention was directed at frantically strengthening his firewalls.

He had to get this out of his sensor suites—he couldn’t even risk _looking_ at it directly until he was sure he wouldn’t spread it further—

Loki flicked a hand and the door clapped shut. “Nothing there. We’re in a special little dreamscape, under the heaviest warding spells I could conjure. I shan’t say we can speak freely, nor plan freely, not against an enemy so pervasive, but we are slightly... safer, here.”

Tony turned and leaned against the shut door. If it was in his head, could he imagine the armour appearing about him...? Apparently not; he stayed stuck in shirt-sleeves. “The blood. I bit your hand.” And had infected himself with nanites or alien magic, Jesus, he was an idiot. Above them, in the waking world, all his pings to the armour went unanswered—truth or lie? Cameras didn’t show it being moved—Loki was blocking this sense, too, somehow, more thoroughly than if SHIELD had dumped the armour in a lead vault. Tony wanted it with the sort of intensity that he’d once wanted approval or booze or to find the key to artificial intelligence.

_Signal boost. Armour. Get it here._

_Don’t think abou_

“Just so. I do apologize for goading you into it. I have far too many eyes on my these days, and many of them are unfriendly.”

“Including mine,” Tony pointed out, crossing his arms. Damnit, that was a defensive tell. He couldn’t help it. The urge to fold in on himself was only barely held at bay.

“Yes, for which I am sorry, Stark,” said Loki impatiently. And tiredly.

_This is what he wants you to see. And... knows you’ll distrust..._

“Right, apology not accepted, so you can fuck off, now.”

“It costs you nothing to hear me out.” Loki had his hands up and open, a gesture of peace. _Hah._

“Please give me some credit for not being quite that stupid.”

“I do. But you’re also stuck in this dreamscape for the nonce, so you might as well listen to me.” Loki paused. “Hear me out, and the spell will unravel on its own; you might even have the chance to see how it works.”

Tony clapped his hands over his ears. “La la la la, I’m not _listening._ ” If he managed to rip it apart on his own, he’d also get to figure out how it worked.  The surest way to guarantee a virus couldn’t affect a system was to made the system incompatible. Extremis had a visual basis; he’d always worked heavily with visuals...

_Changing that would take too long._

“Let me try appealing to your notion of self-preservation, then.” Loki’s words weren’t muted at all by Tony having his imaginary hands covering his imaginary ears. “Thanos has slain the Living Tribunal. You’re not an idiot, Stark—you can find a way to verify that independently of my words: the death of the Living Tribunal has sent shockwaves through the whole multiverse. Thanos won’t stop there. He’s merely licking his wounds, and when he regains his strength... well. With the Living Tribunal gone, there’s no being in this multiverse that stands half a chance of stopping him, not by outright force.”

 _Accept that I have to take some risk and move on._ If he couldn’t change mediums, he could scramble the one that he had. Like putting on a pair of glasses that inverted vision—it was still possible to navigate reality, and in time it grew _normal_ , but based on how Loki’s virus worked the inversion should frustrate it. _Should._

“But this multiverse does have some defences remaining to it, to those who know where to look and how. Unfortunately, those defences are, let us say, well-hidden. Difficult to reach. And we don’t have much time.”

He could read frequency just as well as he could read space. Decompose the data into ten thousand harmless layers—add in some junk he could easily read around, just to be sure—then filter, apply a fast Fourier, super-impose—

 _I’m an idiot_ _,_ he had time to think as frequencies added up in a way that—everything blinked. The feeds from the cameras cut off; the signal of his armour went silent. The room was the same, but now his wrists were pinned to the walls, leaving him wide open and helpless. Loki, across the room, looked both faintly irritated and faintly smug.

“You’re going to have to be more creative than that to get around _my_ spellwork, Stark. Don’t worry. I’m sure you have it in you. But not, I think, before you have time to fully hear me out.”

Wide open and stuck in his head, Loki closer to his own thoughts—

_Don’t thi_

Loki looked at him. It made Tony’s skin feel like getting up and crawling off his body to hide under the bed. The knot of panic at the base of his skull was spreading, a cancer in intangible form, down through his spine, into his heart and lungs and stomach, out to his limbs...

The firewall. He still had firewalls up. There was a way—there was a way to—

“As flattering as it is, your paranoia about me is starting to reach ridiculous heights, Stark,” said Loki, and his smugness had vanished. He looked tired again. _A lie._ “I’m anchored to this multiverse just the same as you—much more so than you; you, being mortal, would be far easier to transport to another multiverse. As has been demonstrated.”

“You know, you’d have more luck lying to me if I hadn’t been there the entire time,” rasped Tony. He swallowed; he hadn’t realized his throat was that dry... except it wasn’t, not really. “Or maybe if your nickname wasn’t Loki _Liesmith_.”

_No, sto—st—let him talk, let him say whatever it is and go away please go away_

Loki gave a _tch_ of irritation. “ _You_ saw the final scene. You saw nothing of the first four acts. The Norns consigned me to bloody torture and then an ignominious death; is it so strange that I objected? You did.”

“Don’t flatter yourself. You’re nothing like me.”

“Oh? I escaped the second, but not the first; I turned my tormentors’ own scheme back upon them and burst from my cave to reign down fire and darkness upon them, rising as a god reborn, more powerful than they could ever have dreamed once I broke my chains.” Loki’s black eyes glittered with—no, his eyes were green—something shifted, in his pupils—“We are almost exactly alike, Stark; we differ only in degree— _I_ am a _god_ , after all.”

No—it was _laughable_ —if only he could think—“I didn’t set out to kill everyone.”

“Neither did I, Stark. But as we’ve both learned, actions have consequences.” Loki opened his palm upward, a small gesture to indicate their programmed surroundings.

_Extremis._

_11094650 infected—_

_No no no no I didn’t_

“Those worlds were collateral damage, as was yours, to you. But I digress. The scheme that broke my chains was the result of eons of planning, trades of magic and power that... well, there’s just no time for me to arrange it again.” Loki’s expression twisted as though he’d bitten into a lemon. “Perhaps the Norns had the last laugh, seeing me escape their plot to a world soon to fall under Thanos’ eye. Regardless—be assured, Stark, I am _stuck_ here. I therefore have great reason to work to see this multiverse survive.”

He couldn’t speak. He might as well have been overclocking his brain again—it wouldn’t have mattered, almost all the data was garbage. There was nothing left for meaningful conversation; some bit of him was recording this, but there was nothing—he couldn’t—

“Unfortunately, gathering this multiverse’s weapons is going to be difficult. And too much time is being spent by her guardians on defence—gods are _dying_ even as we speak, defending _mortals_... never mind. I had thought you might serve as an excellent piece of one puzzle... but then I saw you again.” He smiled. It wasn’t quite the Cheshire grin. “And I saw how metaphysically _interesting_ you've become. Wherever _did_ you lose your soul?”

One step forward—Loki raised his hand and Tony flinched, couldn’t help it; he shrank back against the wall and practically tried to phase through it, he was shaking hard enough—Loki laid one long, white finger against Tony’s forehead and the white, sharp static rose, nearly drowning him—

Loki stepped back, and Tony gasped for a breath that he couldn’t catch.

“You might be a bit... damaged,” said Loki quietly, “but you’re surely less damaged than anyone else shall become, if they attempt to enter that place. The weapon that can stop Thanos is called the Stone of Time, and it is hidden in the Ginnungagap, where even I dare not go again. But you may walk there without any fear except that which you bring with you.”

He looked almost concerned. Tony felt something jump in his throat; he let out a strangled sound, so twisted it took him a moment to realize it should have been a laugh.

“Without the Stone of Time this plan fails,” Loki went on, almost conversationally. “You’re the only one who can retrieve it. So pull yourself together, Stark. Or else, when _this_ multiverse dies... you shall, once again, be as complicit as me.”

Oxygen. Oxygen, he needed air—Tony sucked in a long breath and sat bolt upright on his cot, shaking. Information flooded in—camera feeds, the ping of his armour, telemetry from satellites overhead. He shut the bulk of them down and streamlined his processes, cutting extraneous data movement and partitioning a section of his mind to keep a lock on everything else.

Rhodey was gone, his chair empty. Where—

_Oh, christ, is he still in my head?_

The door opened; light poured through the doorway, and Guindi stuck his head in. “Mr. Stark? You okay?”

“Fine,” Tony breathed. The plate of the arc reactor was hard and flat beneath his fingers—one firm point of contact. _Confidence._ Rhodey was—camera feeds showed him leaving. Could he trust those? He raised his voice, letting it project—“Just a fucking dream.”

Timestamps showed he’d been asleep for nearly nine hours. _Goddamnit._ Quarantine was over and he wanted out, he wanted his armour.

Where the virus had been bits of code lay in tattered ruins. Some sort of self-destruct— _he_ certainly hadn’t managed to damage the damn thing. Was it worth trying to autopsy it? _No._ Probably not. Quarantine, quarantine, quarantine.

“Do you want to talk about it?”

“You’re a fucking nurse, not a shrink, I’ll let you know if I need you to take my blood pressure,” Tony snapped. “Until then _fuck off_.”

Guindi retreated.

The code was shredded and his brain was still twitching, churning out white noise and filling up needed RAM with crap, useless data and white noise. Did that mean that this—thing—whatever was wrong with him, wasn’t something Loki had shoved in his head? Or was there a second layer to the virus that he hadn’t found yet? _Or it could be both. Fuck._ He drew his legs up until he could rest his elbows on them, and pressed his palms against his temples.

Streamlined processes didn’t mean a lack of physical security, so he had warning from the hall cameras that Natasha was standing at the door to the room. She knocked, though—a courtesy of a different sort; she didn’t wait for him to answer before slipping inside. Her posture was casual, nonchalant—

_And how much a lie?_

This was ridiculous. He couldn’t treat Natasha like Loki.

_Unless she is—_

_Fuck OFF._

“It’s funny, how you can be great at lying one moment and then suck at it the next,” Natasha said after a minute. She was leaning casually against the wall that Loki had pinned him to, hands in her pockets, a messenger bag hanging from one shoulder. Keeping the doorway clear.

“Yeah, well, we can’t all keep it up twenty-four/seven.”

 “Wow, harsh.” Her dry tone told him exactly how much she cared. “Steve’s in DC for an emergency meeting. He’s probably in blackout, but I bet you can get around that—he wanted you to call him when you woke up.”

“Maybe later,” Tony breathed, half-muffling it with his arms.

From the way her eyebrows drew down and the slight upward turn in her mouth disappeared—he didn’t need to be looking at her with his eyes to see her, not these days—she _did_ care about that, and he immediately regretted saying it. She let the silence hang for a few seconds, but he knew that trick, and even if he’d never had the patience to use it himself, he did have the patience to out-wait it. _only took getting fucked up for the_

He cut the thought off. He did it without _stop_ , even.

When he didn’t say anything, Natasha let it go—or, more likely, changed tactics—and tossed the messenger bag in his direction; he made no move to catch it, and it landed on the cot with a thump. “Here. Clothes. Yours are still off-limits—the techs are _very_ impressed, by the way, and also very afraid of you considering extremis is a BSL-4 biohazard. Or was.”

“Steve told them better.”

“Steve isn’t _here_ , and he’s in a blackout zone.”

 _which won’t matter one damn bit if he_ “If they start fucking with now it it’ll just go inert.”

“Oh, they know better—there was only one who wanted to dissect you, and Steve got him thrown in holding.”

Camera records showed Steve hovering in the doorway six hours ago, far less nonchalant than Natasha was now. Tony was—apparently—curled up on his side on the bed, asleep. Had Loki been ripping through his head by then? Steve had stood there for five-point-two minutes before leaving without ever fully entering the room.

“Get dressed. We’re going out. Coffee.” Natasha slipped out the door.

_What the hell._

“This is Romanoff. I’m taking Stark out for a coffee.” 

A pause. “Acknowledged,” came over the same command channel. It was a very unhappy acknowledgement. 

When Tony was dressed, Natasha slipped back in. The clothing smelled new, of harsh chemicals; he’d probably wind up with dye ground into his skin. The cheapness of it, and of her own outfit, cued up memory files of the other Natasha. She’d taken him out and around, too.

_But not for coffee._

“Come on,” said Natasha, leading him out.

His previous strolls through the building mainframe meant that there were no surprises left in this place, but all the construction in the hallways nagged at him. The NYHQ boasted a staggering number of sub-basements, even by his standards, but all the really interesting experiments had been located out at PEGASUS—before Loki-the-lesser had trashed the place, that was. The new facility, named in typical SHIELD fashion ‘Project Horizon: Exploration and Outreach to Newly Identified eXtraterrestrials’ had gotten tied up in red tape after SHIELD had gone public and Fury had decided to have a pissing match with the WSC.

Now, however, Cold War fallout-shelter-cum-office space was being rapidly converted into labs. Somebody had gotten tired of waiting for PHEONIX to rise from the ashes of bureaucracy. Half the sub-basements were under construction, crews working on plans laid out for equipment still in transit. Not exactly shiny-new equipment, by those invoices: it had been confiscated from various unfortunate universities and private institutions. It looked like in some cases they’d confiscated the personnel, too, or else bribed them with shiny, shiny knowledge. And bribed them _fast_ —in the last nine hours, SHIELD HR had increased the New York science contingent by half, gutting its other bases in the process, and there were enough flagged-for-interview files that if SHIELD hired on even half of those identified, it would be tripled. Why?

There were holes in walls, where technicians were installing more security. Nobody looked up at Tony and Natasha as they passed, but Tony kept his head down anyway. Blond had been a good disguise...

Natasha tucked her hair back and pulled up the hood of her hoodie as they stepped outdoors, completing her disguise, such as it was, with a pair of glasses that she didn’t need. It was raining, a cold drizzle, and she handed him an umbrella and opened up her own. Tony glanced back at the building as they walked away. Its mirrored windows gave no clue about the activity inside.

“You can keep us off of any cameras, right?” Natasha asked as they strolled away.

“Sure.” He even had the ICG, still, for all that he didn’t have his armour—he could vanish, duck away and Natasha might never find him...

_Secret’s blown, live with it._

Easier if he knew what he was living with. He set part of his brain to a second, deeper search through SHIELD’s databases, chasing up requisition orders to find out where they were coming from, but it felt a bit like trying to look around a black hole. Directives were issued, orders given... but where was the vision that pulled it all together? What was SHIELD after, here, beyond trying to reincarnate PHEONIX? Something with other worlds, obviously. But what?

The NYHQ had been built out of the old SSR building in Brooklyn, which meant that there were five coffee shops within a two-block radius; three of them were Starbucks, and it was the second-closest one that Natasha led them to, one packed with twenty-year-old kids wearing old-fashioned scarves and skinny jeans—all self-absorbed in their own little groups, not inclined in the slightest to look at anyone else in the place. Natasha ordered for both of them while Tony focused on not twitching every time a teenager laughed too loudly.

How many kids had extremis killed?

_I could have saved them._

“Come on,” said Natasha brightly, appearing in front of him with two cups.

Back out into the rain. He held Natasha’s umbrella and coffee for her as she pulled on a pair of stylish gloves, and then they walked further on to where the buildings made way for trees, one of Brooklyn’s urban parks. Mostly empty, given the rain, and Natasha led them well away from those few souls either brave enough or unfortunate enough to not put off by the downpour.

The ever-present cameras yielded up their captures to him as easily as anything else; he fudged his face and Natasha’s with subroutine run from the back of his head. Not something he needed to think about. Those cameras were barely of high enough quality to identify a mugger.

They strolled further into the park, and still Natasha didn’t say anything. It was starting to make him nervous. _She always makes me nervous._ At one point, that had been a lie...

His patience wore out first. “Did Cap ever tell you about the other you?”

“Mm, a little. Is it going to cause a problem between us?”

“No.” It couldn’t. “Why’d you rescue Pepper?”

“I like her.” She glanced sideways at him and smiled at whatever she read in his expression. “Sometimes it really is that simple.”

“Uh-huh.”

“Why’d you come back with Steve?”

“He asked me to,” said Tony, and the shiver that went down his spine had nothing to do with the chill of the rain.

“He didn’t lock off your armour because we were trying to punish you, you know. You had a seizure in the quinjet; it seemed like a good idea to get as much extremis away from you as possible.”

Tony swallowed. “Integrated system. Didn’t made a difference.” Except denying him RAM and processors that he could have used.

Natasha’s voice was soft, barely audible over the rain, and dead level. “What did he do to you?”

_Got inside my head._

_Found out—_

They weren’t talking about Steve anymore. Were they? Tony picked up the pace, drawing ahead of her. The skin on the back of his neck crawled.

She let him alone for a minute, trailing just behind, and then stepped up enough to be side-by-side again. “You know that saying about it not being paranoia if they really are out to get you? It’s also paranoia if it’s getting in the way of _stopping_ them from getting you.”

“And what the hell am I supposed to—I can’t... stop him.”

“Hey.” Natasha put one hand on his arm; he flinched backward, and immediately hated himself for it. She didn’t let go, though, drawing them both to a halt. The nearest homeless guy was at least a hundred metres away; no one else was around. “We’ve done this before. Beaten impossible odds.”

_I wasn’t fighting the inside of my own head_

_I could_ think

Her eyes were too assessing. He remembered the profile she’d written about him—so much truth, just a little bit of lying, and he’d _known_ he was walking right into SHIELD’s clutches when he’d read that last line, but he hadn’t been able to stop himself; she’d known exactly what bait to lay. He wouldn’t be able to stop himself when Loki twisted up his thoughts, either. At least with SHIELD he’d seen it coming, but now every thought tripped over itself, and—

“Hey,” said Natasha again, firmer now. “Stop. Re-evaluate. If the objective is impossible then you need to re-examine either the objective or your resources. You’re not alone anymore—you don’t only have to rely on yourself.” She paused, and one corner of her mouth quirked upward in a wry smile. “Although considering that you know how to build portals to other worlds, I’d recommend also getting help from yourself.”

Get help from—that sounded like a _terrible_ idea. “Did you even _read_ Steve’s report when he got dropped back the first time?”

“I did. So did Hill and Fury.” Natasha was... _shit. She’s serious._ “One of the worlds he wound up on was just a few years more advanced than ours—peaceful, willing to help him. We could use that help. It makes sense.”

“It does _not!_ ”

“It’s not you alone anymore. If you build the portal, we can screen them.”

“Right, while you’re screening for Council spies.”

“That’s already being dealt with—Hill pulled out one of the fallback plans for dealing with Council interference, Operation Alexander. Set up a subdivision within SHIELD with non-standard screening of everybody who gets access, then reallocate resources via some creative methods. We modified it to stick the Avengers at the top. I’d like to think that between Clint and myself, we have a fair amount of expertise in sorting out who is really on-side.”

“And here I thought you’d be busy playing parole officer.”

Natasha let go of his arm, stepping away a bit—just a bit. Space, air to breathe. Her expression was sympathetic—was it real? “That won’t be forever. And”—her voice was brisker—“the terms we have only require one of us nearby. If Bruce moves his research to the NYHQ, you’ll be fine for your own lab.”

He didn’t know why he was complaining. There was—of all the things to whine about, needing a friend to sign his hall passes was so far down the list as to be off the page. It was ridiculous to be bothered by it—ridiculous, stupid... 

With satellites clear overhead and live cables running beneath his feet, SHIELD’s network was easy to access. He dipped back into it, hunting through recently changed files. Too much pertained to him and told him nothing he didn't already know. He stalled, staring down at his coffee. “Other worlds... they have their own shit to deal with.”

“This is their problem too. But we’ll screen them—we being the Sentient Worlds Outreach and Research Division. Sorry about the name, it’s SHIELD humour.” Natasha met his look with one that came from beneath lowered eyelashes.

The name gave him a file stripped bare of nearly all useful info: they really _weren’t_ doing this where the Council could see it. Tony sank hooks into the data and pulled it apart, backtracking and rewinding until he started getting results. Division Director: Maria Hill. Oversight by: Steve Rogers, Natasha Romanoff, Bruce Banner, Clint Barton. Purpose... blacked out. Natasha made it sound like there were _plans_ ; they were either not written down, or were secured on a completely isolated server. Well, he could guess at their purpose well enough: Natasha could dress it up however she wanted, but at the end of the day it was about finding leverage. Weapons.

 _Weapons like the type I said I wouldn’t make, huh?_ “You’ll need to be careful. They’re not... people are _not_... the same.” The other Natasha had killed her Clint, certain that he’d betrayed them. Was she the one who was—wrong, flawed, unskilled—or was it that this Natasha was too trusting?

_Did I seriously just wonder if the Black Widow is too trusting? She’s up to something. I can’t—_

_Steve asked. ...Asked. I agreed._

“I know,” said Natasha—every feature, every frequency in her voice identical to the other’s.  

Tony took a sip of coffee. Black, Starbucks, terrible—the first coffee he’d had in months, it was like ambrosia. How many swimming pools worth of coffee had he drunk while working on shit in his lab? Okay. SHIELD—Natasha—wanted a portal, enough to wall off a whole division of scientists and analysts for this ‘outreach’ project of theirs. _Steve_ wanted a portal, Tony could build him a damn portal. “Fine.”

Natasha nodded. “What do you need to make that happen?”

“I need my armour.” It was even true. “I need a facility with space-grade radiation shielding containing a free area of at least ten by twenty by five metres. I need that supply of iridium that I know SHIELD has.”

_Or—_

_No._

_Well._

_Oh, fuck it, just fucking do it—_

Natasha was silent, watching him, her expression unreadable. Or... not unreadable. Not-judging. It was like she’d put aside anything but her mission here, and none of it could touch her; the world could end and her focus would be crystal clear.

“Everything else I need is in a cache in Oregon.”

“Alright. Do you want your armour first, or do we both fly in the quinjet?” She steered him around in a one-eighty, back in the direction of the NYHQ.

_Funny how quick you agree to the armour_ now _._

“Armour first. Then quinjet. Quinjets. I’ve got a lot of stuff there.” _This may have been a terrible idea._

_Fuck it shut UP, you said it, it’s done._

 


	4. Shield and Sword: 1.4

Getting the armour back was like waking up, except that the nightmare didn’t fade away.

With the armour everything was faster, clearer, _better_. It had been shielded from most of the cascade of errors he’d experienced earlier. He flashed through a debug, but the armour’s updates had kept compiling on its own and finished while he was out, perfect like clockwork, a distinct lack of fuzzy-logic _anything_ to fuck things up here. 

He didn’t bother stripping to put it on, just picked up the clothes that it looked like it was and felt the connections slip into place, a band around his chest snapping, a blindfold tugged away. The mass of armour nanites flowed over his skin and underneath the clothes Natasha had brought him, reforming beneath with enough bulk that the fabric ripped. He stepped out of the shreds of it and looked down at his gauntleted hands.

“So that’s what it looks like when you take the red pill.”

 _“You should see it from the inside.”_ It came out like thought—it _was_ thought: he hadn’t spoken save through the suit's speakers. A trick he’d had for a month and now it just made the inside of his helmet sound hollow.

_His name is Loki_ Liesmith _for christ’s sake._

The repulsors gleamed up at him. When the hell had he started needing other people to tell him where to point them? He’d left that behind in the sands of Afghanistan.

SWORD was designed to combat a threat that came from outside the multiverse. Thanos was bigger than Loki, metaphysically and physically; bigger event, bigger disturbance. He'd seen for himself the way Thanos bent space-time. If he could quantify and locate it, he could figure out whether Thanos was _here_ or only had been. He needed—

—an astrophysicist—

boot hit a solid that gave way beneath it; nearby, tiny, high-pitched sounds of

—he needed to think.

On the plus side, he’d be surprised if Thanos actually gave a crap about some random, puny human, so he should have a bit more breathing room than with Loki. On the negative side, there _was_ Loki.

“Should I be worried that you’re pointing a loaded weapon at your head?”

 _“Is that concern I hear from the Black Widow?”_ He dropped his hands back to his side and let the armour reform into heavy clothing.

“You _are_ wearing the T-Virus.”

“Don’t worry, Alice, I’d never forget you can kick my ass.”

“That _is_ what worries me.” She tilted her head to the side, catching his gaze. “I know how it is, when there’s no one to trust. I know what it makes you capable of. I got stuck in Shenzhen too, Tony—if I’d been bit instead of Steve I wouldn’t have survived.”

Fragile wasn’t a word that was _used_ to describe the Black Widow.

_What about mortal, though?_

She was screwing with his head, making it harder to sort through. She always _had_ been; that was what she did, even to people she liked.

“Make sure we’ve got pallet jacks,” he told her. It wasn’t important. Whatever she was doing, it didn’t matter. The real problem was bigger, so much bigger, and he didn’t even know what it looked like. Yet.

She tapped her radio pointedly, giving directions in a cool tone. Tony ignored the gesture. He had the full armour back, and the software upgrades were all in place, but he couldn’t shake off the feeling that something was still wrong. He couldn’t be sure Loki’s virus had decomposed entirely. What if he’d missed something?

“Come on,” said Natasha, heading for the door. “Our ride’s here. Unless you plan to be your own ride.”

Had that been a sincere offer on her part? “What, not afraid I’ll fly the coop?”

She snorted. A technician working on installing conduit caught sight of this and paled; Natasha gave no sign that she noticed. “Asking this after I took you to Starbucks?”

“Didn’t have my armour.” Whereas she was never without her skillset.

“You have an invisibility cloak.”

“Like you couldn’t put me down blindfolded.”

“Maybe. Probably not without you infecting me with extremis.”

_Christ._

She turned to face him—he’d stopped walking, he realized belatedly, and shit, wasn’t _that_ a red flag. He took an internal snapshot of his run processes, but the code seemed to jump around in his head—fuck, he _must_ have missed something. This was fucking unstable. He was unstable.

It didn’t even seem worth it to protest that he’d taken that capability out.

“Then again,” said Natasha, “You could have infected me at another time, instead. Or Guindi, if you wanted—or manufactured aerosol nanites and taken out most of this base and then the city. Keeping your armour away from you was never going to make you ‘safe’ to _us_ , Tony, if you really didn’t want to be.” She smiled slightly. “As it happens, I have some experience being there, too. So does Bruce. Welcome to the club.”

what

He could side-step around her. The feeling of the tech’s eyes on him was both lessened and heightened by how he could watch the guy right back, through the security cameras and through the 360-degree sensors of the armour.

“Let’s just go.”

“Right,” she said, and led on toward the hanger bay.

He let his focus tick over the three quinjets there as they entered. Clean drives, clean systems, no foreign signals... no dings in the paint, either, and he knew how SHIELD pilots liked to treat their babies. “What did you do, get them fresh off the assembly line?”

“Seemed wiser,” Natasha said blandly. “Is Steve still in a blackout?”

That made it sound like he’d been keeping tabs on Steve. Tony abruptly wished he’d left the helmet on, even though she wasn’t looking in his direction—deliberately, no doubt. Were there reflective surfaces she could—? He cut that thought off and sent a ping off to Steve’s comm. When it didn’t return, he tried not to feel relief.

When Steve found out that Tony had had Loki in his head, that he might _still_ be there, and that Loki might know—

— _no—_

It was _Steve_. He wouldn’t—even when they had fought before the Window of Time, it had never occurred to Steve. But that was before he’d seen Tripitaka use it to stop him so very effectively, to grind him into the ground; before they’d returned to the Ohio mine and Steve had sounded so _tired_ as he told Tony to call SHIELD, and hadn’t answered to _and what if I don’t_...

Steve was a soldier; he’d fought in a war.

At least if it was Steve using it, Tony would know he deserved it. But even knowing that... his mind kept trying to cringe away from it; he couldn’t properly _think_. It was like wordless static, buzzing at the back of his head. He couldn’t differentiate it from the background errors.

“Tony?”

Natasha was looking at him now, concern in her expression. Tony tried to swallow, then ruthlessly suppressed the urge and rewrote a tiny bit of code from his endocrine system so it wouldn’t happen again. Extremis obediently moistened his mouth enough to speak. “Uh. Yeah. He’s still off-grid.”

“Hmm,” said Natasha. “I’ll text him, then.” She pulled her phone out and ducked up the ramp to evict the pilot, typing one-handed. hey w friend gone 2 get supplies call me when ur out :)

Tony elected not to comment on the smiley-face. He stepped up the ramp and past the pilot as the slump-shouldered young woman trooped out, eyeing Tony with annoyance that was oddly, comfortingly familiar. At least he was _used_ to annoyance.

Natasha strapped in and ran through the pre-flight with admirable speed—he hadn’t thought she was much of a pilot. Maybe she was branching out. It would have been easy to hack her record, see when she’d qualified and what flight hours she’d logged, but he didn’t bother. He had the armour, after all. Hell, he had the _jet_ , if he... needed to commandeer a quinjet for whatever reason.

She’d been wrong about his ability to infect other people with extremis—had Steve _not_ told them that he’d disabled that? Why _not?_ —but with his armour back, there wasn’t anything that they could do to him without Steve. Was there? Was she just trying to tip him into overconfidence? How many men had the Black Widow brought down that way? Fuck, he’d seen her do it to Loki—little Loki, confused Loki... not the one who might still be in his head.

_Don’t think about th_

“Coordinates in your nav,” he told her.

They took the flight at supersonic speeds, after reaching an altitude high enough that the sonic boom wasn’t such a problem. With Natasha to fly the jet, Tony dumped most of his processing power into the bigger picture. Loki could be lying: but if he _was_ telling the truth, they were screwed. Tony had a starting point in his sensor readings of Thanos, but there had been too much going on at the time. He wasn’t even sure if he could trust all of his readings; Tripitaka had—

_..._

He set up analyses and simulations to run against, dozens of different filters, different ways of twisting it in and out... he needed to view this picture from all angles; he only had the one point. He refrained from hitting run, though. If Natasha was actually going to just _let_ him at his Oregon stockpile, he’d be able to run such calculations at far greater speed once he had it.

“Where are we landing?” Natasha asked as they drew near enough drop down out of the clouds and toward the back-of-the-way commercial storage lot that Tony had rented out.

The parking lot was half-full, but even if it hadn’t been, there wasn’t room for more than two of the jets to land at once. With the cars in the way, one would be a tight squeeze. He could manage it just fine, if he took over the controls, but he didn’t know about Natasha.

“Can’t you boot them out? You’re the government agency.”

“It’s called being discreet.” Her eye-roll was practically audible. 

Tony raised a pointed eyebrow back at her. SHIELD hadn’t found this place. He could do discreet.

“Or at least polite,” she conceded, and clicked the radio. “Aleph-Two and Three, prepare for a joint airlift. We’re taking the entire cargo cube.”

He couldn’t help it; he laughed.

Natasha eased them downward, nestling them in among the cars with annoying slowness, but at least she didn’t scratch any. “If there’s anything you want out of there beforehand, we should grab it now.”

“And deactivate the security.”

“What did you set up on it, anyway?” She sounded curious in a not-wholly-professional way. “This is a civilian area, you could have had people wandering in accidentally.”

“Not that easily. These guys have a good reputation. If you want to be _polite_ , you’ll probably need to make nice with them about grabbing one of their units.” He led the way down the hatch; he could hear what he’d left here, beyond, and the relief that it was still there... even though he’d _expected_ it to be there. He and Steve hadn’t actually been _gone_ from Earth for any appreciable amount of time, this time, and he hadn’t been pinged by any of the tracking programs he’d left behind.

He’d have to upgrade it with everything he’d learned in Maklu, of course. But that was a long way from starting from scratch.

He gave Natasha a boost over the fence enclosing the storage cubes, seamlessly cutting into each security camera feed as it would have come to bear upon them. Natasha’s directive to the pilots made sense; the cubes were designed to function as shipping crates, too. Each was an entirely closed environment. The one he’d bought had been the largest type, only shippable if you could shut down two lanes of a highway—or if you had quinjets able to airlift it. Calculations ran in the back of his head. The container was designed to be lifted, although not in high winds... he formed a solution and set it over to the other two quinjets, tossing it up on their HUDs.  

“Here we are,” he said at last, jogging up the temporary wooden steps to the door. Equations and key-locks ran through his head. It _wasn't_ secure enough, he could see that now. He’d hidden this place in plain sight, but that had its own dangers. He should have done better. It was too easy to disable the imploder and click the locks open.  

“Do you have an inventory list for this place?” Natasha asked, as he formed a repulsor node on his palm and let it shine brightly enough to illuminate the depths of the inside.

The storage cube—a cuboid, really—was packed tight, everything tucked away with a machine’s precision, because he'd been one when he’d designed it. After he’d set up the site in Ohio, it hadn’t been needed, but there’d been no point in throwing it away. An emergency, mobile fab shop had a hell of a lot of advantages.

Not all of its capabilities were geared toward production, however. He wandered down the narrow walking space, which just wide enough for one of the armours to squeeze through, and stopped before a two-metre high cabinet.

Or rather, it looked like a cabinet, in the same way that his clothes looked like clothes. It, and everything inside it, added up to six cubic metres of additional brainpower, already set up and attuned to him. It didn’t have the higher-logic, fuzzy decision-making capabilities that the processing nodes inside his brain did—and he’d have to upgrade all the software again—but this was what he needed to be able to properly multitask.

“This one comes with us.” Getting the whole cube back to New York would take hours; there was no rigging solution he could devise with the materials on-hand that would stand up to supersonic flight.

“How are you going to get it out of here?”

“Door in the back. You brought that pallet jack, right?”

“You’re the engineer, but I don’t think it’s going to handle a three-foot drop.”

Tony frowned. When he’d put this together he’d done so in pieces. He could disassemble it, but this batch of extremis wasn’t designed to be mobile the way his armour was. “Owners of this place might have something.”

Cameras showed that there were a number of employees on site: one showing around a prospective customer, a couple of security guards, somebody working reception and currently on the phone... Tony considered his own appearance, and Natasha’s. Nobody in Starbucks had recognized her.

“You’re the legal owner of the cube, right? You can just have it picked up and shipped anywhere?”

“Sure. Not looking like this, though.” What identity had he created to rent out this place? Files, files—aha. A woman? Why had he done that?

“But you’ve got illusions you can cover that up with.”

Power levels pinged at the edge of his vision. He repressed a grimace. “For maybe ten minutes.” Upgrades—both an upgraded arc reactor and ICG—were critical, but that was part of why he needed the storage cube in the first place. Just as the nanites in the armour weren't designed for brain-boosting fuzzy-logic, neither were they, nor the nanites in his body, designed for more than basic fabrication and repair.

“Can you change the armour so you look like a SHIELD commando?”

“Gimme a minute.” That wasn’t a pattern that he had hard-coded; he input variables and scripted on the fly, letting it flow up and around him. Plenty of visual references were available to figure out how SHIELD commandos looked. He chose one that included a fully-covered face.

It took a bit longer than five minutes, and at the end, Natasha eyed him critically. “We’re going in there. Make whatever ID you need. Don’t talk more than you have to, and don’t scare them; that’s my job. I don’t want any panic about extremis here.”

“Fair deal,” he agreed.

“Then let’s go.”

They exited the cuboid and she pulled out her own SHIELD-issue AED, turning it up high enough to confuse but not offline all the cameras nearby—that would get security’s attention, and bring them running, in three, two... Tony watched as the guard in the security room radioed the one on patrol, trying a remote restart of the cameras: the AED wasn’t capable of cutting him off, not at this range and with the armour. Natasha sauntered across the parking lot like she owned the place and also wasn’t planning to stick around long; he followed in her footsteps, aware that he probably wasn’t getting the gait just right. SHIELD’s agents had that way that they walked, like they were in training to be Natasha.

They ran into the patrol guard coming over from the opposite end of the lot. “Excuse me! Excuse me, ma’am, uh...” He seemed to register the ‘gun’ that Tony was carrying, and tensed up, reaching for his own—no, that was a taser. Credit to the guy, though; he didn’t try to pull it. “Look, I’m sorry, but for security reasons we need all customers and prospective customers to be escorted by—”

The security guard in the camera room hit a bit red button; Tony blocked the signal it tried to send, along with the internal call she tried to put out over their radios. “That guy has a SR170, I’m calling the police. This is a general evacuation call, we have armed intruders on-site.” 

“I’m Agent Romanoff of the Strategic Homeworld Intervention, Enforcement, and Logistics Directorate,” Natasha interrupted smoothly, flipping open a badge that Tony hadn’t even realized she’d been carrying. She kept walking toward the front office without slowing, catching the security guard up in her wake. “You have onsite a container that one of our agents bought from you several months ago. We need to retrieve it.”

“We, um, we have a strict no-weapons policy on the property, ma’am.” The guy— _Jake Harris_ , said his name badge, and _salary of fifty two grand a year, divorcee, two dependants_ said his employee records—hurried after them, but not too enthusiastically.

“We’re federal agents. I believe you’ll find we have an exemption.” They reached the front door; Natasha yanked it open and strode through, instantly getting the attention of the five people standing inside—the security camera-watcher, who had come out asking why no one was evacuating, her manager, who was asking her what the hell was going on, two worried-looking customers, and a receptionist who looked like this was the most interesting thing she’d seen all week. Tony found their basic info and dismissed them all in an instant.

“Oh my god,” said the receptionist, speaking over the immediate questions of the other four. “Are you the _Black Widow?_ ”

Natasha smiled. It was actually a pretty nice smile. “Yes, I am. I need the papers to get storage container—” She glanced at Tony.

“4B, name of Marcia Walsh.” The armour’s speakers pitched a normal, if muffled, human voice up two octaves from his own.

Natasha didn’t bat an eye. “—4B, name of Marcia Walsh, for immediate release.”

“We have a no-weapons on site policy,” said the manager weakly, as the receptionist set-to with a will—and with half an eye on Natasha. _Somebody_ wanted an autograph.

“Ted, you can’t tell her that, she’s an _Avenger_ ,” hissed the female security guard.

“You guys didn’t know you were renting to an Avenger?” said one of the customers to the guard who had followed them in.

“No idea.”

“Well, at least they think the place is good...”

“Ma’am—uh, Agent—” The manager appeared to have regained his wits and stepped forward to offer a handshake. “It’s great to meet you. Honestly, my son is going to—uh. Unit 4B is one of our biggest units, you’re not going to be able to get it out of here unless you’ve rented a flat-bed and pre-booked it with the traffic authorities—um, well, _at least_ you need a flat-bed.”

“Don’t worry about the logistics,” said Natasha, leaning over the desk at where the printer was spewing out papers. “Veronica”—the receptionist’s desk had a nameplate—“can you please indicate where Agent Walsh needs to sign?”

“Yes, of course.”

“Um, we need to do a walk-around, inspect the outside for damage, so you can be sure no one has gotten past our security.”

Natasha smiled at the manager. This was not so nice a smile. “That’s not going to be necessary. Walsh—sign.” She pointed at a cup on the desk that held several pens.

“If we don’t, the liability—it’s tied up in the insurance—”

“Print whatever release forms need to be signed, and we will sign them.” She tapped her radio. “Aleph Two and Three, start rigging. Leave the western side clear for now. ”

“This thing’s going to stand out like a duck on the radar, Aleph One.” 

She glanced at Tony, one eyebrow quirked; he turned so that he could be witnessed seeing it, and shrugged, and she replied, “Add it to the flight plan, then.” The flight plan that they didn’t actually _have,_ but—eh.

“Acknowledged.” A call pinged back HQ for the bureaucratic support.

“And sign—there, there, and there,” Veronica indicated. Tony signed. “And I need two pieces of government-issued ID, one must have a photo—” He pulled out a nanite-created Oregon driver’s licence and American passport and laid them on the table, then activated the ICG and shoved down the balaclava, raising the goggles that were a part of the tac uniform. Marcia Walsh, he decided, was a stone-cold customer; she held her face still and unsmiling as Veronica compared the ID. “Great. And, sorry, I just have to check this against the computer entries we already have—” He nabbed the search results she got and modified them as she clicked through.

“Do you have a pallet jack or a lift capable of removing a three-by-ten-by-seven foot package from the side of the unit? We need to load that separately.”

The manager had started out nodding and then switched to shaking his head. He looked rather helpless about it. “All our units only have entrances at the front and rear. We can’t remove anything from the side.”

“Don’t worry about that part. Assume the side of the unit is missing.”

“I—yeah, sure...”

“Great. Walsh, are you done?”

“Yup, she’s done,” said Veronica. “And. Um. Agent Romanoff, can you please sign this?”

It was a blank piece of paper. Veronica looked very hopeful.

Natasha, poker-faced, grabbed the pen from Tony and signed, _Thank you, Veronica, XO, Natasha Romanoff._ “Walsh, let’s go.”

A quiet “...what the hell do you think she has in it?” followed them out.

 

* * *

 

The tracking subroutine for Steve’s location pinged while Tony was welding the side of the cube back together; ten seconds later, Natasha’s phone buzzed. Tony eavesdropped and tried to look busy.

“Where are you?”

“Oregon. Meeting go well, I take it?”

“Yeah, it—fine. How is he?”

“Welding at the moment, so happy as a bee, _mother_. What does ‘fine’ mean?”

“It means we’ve got USMil support, courtesy of Captain America’s personal guarantee that SHIELD will give everything back afterwards,” said Steve, sounding rather sour about that second part. He really did hate the dancing monkey thing. “I’m coming out there.”

“If you show up here that’ll only convince the locals that this equipment pickup is a cover-up for an alien invasion. Besides, we’ll be on our way back to New York by the time you get here.”

“He didn’t call.”

“Now you sound like a jilted boyfriend,” said Natasha, exasperated. She raised her voice, pitching it to be directed at Tony without having to turn around—he didn’t have a welding screen up. “Will you call him _now?_ ”

 _No way he didn’t hear that,_ Tony thought, and flinched. _God fucking damnit, Romanoff._

He jumped down from the ladder he was using, then picked it up to reposition it on the other side of the cut-out. Hovering with the jet boots would have been easier, but they were trying to be _discreet_ , since the security guards kept trying to come around and gawk after Tony had killed their feeds more obviously. There was a case to be made that he was busy and needed his attention focused, but it would be a lie and Steve—might realize that.

Steve had asked him to cooperate. 

Instead of cutting into the call, Tony went with the more secure route of setting up a direct line to Steve’s comm, bouncing of networks and hiding his tracks as he went. _“Like the lady said, Rogers, I’m welding. Busy.”_ The eyes in the back of his head showed Natasha thumbing her phone off and settling into a slouch. Like that, she looked as dangerous as any other twenty-something kid.

_“Good to know. I’m sorry I couldn’t stick around. Getting SWORD off the ground is kind of a scramble.”_

_“Yeah, well, I’ve been cooperating.”_

_“Thank you,”_   said Steve, and Tony could have choked on the sincerity of it. _“Look, I’m not in a secured area, but when we’re both back in New York, I’ll catch you up on how my debriefings went.”_

And how much he’d told Fury?

_No—he wouldn’t—_

_“Uh-huh.”_

_“We need to talk about what exactly your plans for Rudolph are. And what happened with the operating system. I’m assuming if Natasha took you to Oregon then you got the errors sorted out.”_

His vision pixellated around the edges. Tony snapped the welding torch off as gravity tipped sideways—no, that was just his sense of it—he grabbed onto the ladder with enough enhanced strength to dent the metal, and tipped more processing power into the debugger until it got back under control, and could resume its steady, low-level state. _That wasn’t so bad. That wasn’t so bad—_

_He—_

_“Tony?”_

_“Yeah,”_ said Tony, and since it was through extremis and not out loud, he managed to make it come out perfectly normal.

 

* * *

 

“You’re quiet,” Natasha said about an hour later, as they slowly flew escort back to New York.

Currently Tony had two his hands shoved inside a soup of pure extremis nanites, a direct, thick, superfast connection to the cabinet strapped down against the quinjet floor. He was running through update protocols, trying to figure out everything he’d _done_ in his own upgrades—everything that had made such perfect sense while he’d been hooked into the library node in Maklu—and simultaneously writing out protocols and directions for building an inter-reality portal device. “Uh-huh.”

“At one point I’d never thought you’d be able to go undercover like that.”

“It was five minutes.”

“Playing a nobody? Signing paperwork and doing what you’re told?”

Tony opened his eyes and glared toward the front of the jet. “There was that thing where I ran a Fortune 500 company for twenty years—I’m not actually allergic to signing my name against something—”

“ _Ran_ , yes. No one ever commended your ability to follow orders. I was expecting a bit more pithy commentary. Even when Pepper took over you never shut up.”

A beat. What was he supposed to say to that? He closed his eyes again and dived back into programming.

“If we got Pepper back here, would you talk to her?” Natasha asked, her voice quieter.

 _Probably not. Haven’t yet._ But the thought of Pepper’s presence, her fathomless competence, hell, even the _click-click-click_ of her heels... he shoved it down. Pepper was out. Pepper was on the run and her life was ruined, he owed her a debt he couldn’t repay, but dragging her back into his shit was the last thing that would pay it off. “No.”

“Hmm,” said Natasha.

Tony sighed.

They set the storage cuboid down directly into the attached warehouse—whose roof conveniently could be retracted—rather than in one of the loading bays; Tony had sent structural drawings on ahead to SHIELD about the necessary supports, but Alephs Two and Three still had to hover for half an hour while the ground-crews fussed. More techs swarmed over the site with security measures as soon as the installation was secure. He didn’t stick around; almost everything in the fab unit could be operated by thought, as far as he was concerned.

Even though it was five in the morning by the time they got there, a news crew had pulled up not ten minutes after, filming the not-so-invisible jets as they hovered. Somebody eventually got the bright idea to run enough cables out to power a massive security cloak over the entire area, but by then there was already footage, and he heard Hill nixing the idea on the radio: “Put that thing away _now_. That is classified technology and we are not showing it off in front of cameras!”

Hill wasn’t the only new addition to the NYHQ; while more techs unloaded the processor-bank cabinet to be installed in a workroom, Steve showed up to hover at Tony’s elbow. He looked tired—he must have grabbed a shower since the last time Tony had seen him, but Tony would have been surprised to hear he’d caught any sleep. Even the serum could only do so much.

“I should have come out to Oregon with you,” Steve said, giving Tony a concerned once-over. 

“It was a field trip, relax. I had Natashalie there to babysit me.” That got him a frown. “Not that I needed babysitting. I’m cooperating. _Cooperate with SHIELD_ , you said.”

“That wasn’t exactly what I said, but thank you.”

“Whatever.” Tony ran a hand through his hair and resisted the urge to cross his arms over his chest; then he decided he could get away with it if he glared at the techs instead.

“We need to talk.”

His fingers tightened against his elbows. “So you said.”

“Not here,” said Steve, and then, quietly enough that no one without superhuman hearing would pick it up, and keeping his lips still enough that probably even Natasha wouldn’t have been able to read him, “I left out a lot when I was briefing Fury. You should know what.”

“Natasha didn’t ask me anything in the jet. Not about that, anyway.” Which was more than a little odd, now that he thought about it. _Unless she just didn’t want me knocking the fucking power out._

 _Speak of the devil and she appears._ Natasha finished up her post-flight check-in then, upon which he’d been eavesdropping only idly, and joined them in staring at the techs. “Steve, you look like ten miles of bad road.”

Steve rubbed his chin—there was actually stubble on it, for once. Even on the road with Tripitaka, he’d managed to keep mostly clean-shaven. “Everybody wants their own set of paperwork. Haven’t had time to sleep.”

 _And you were waiting up._ “Make some now,” said Tony—too abruptly; they both looked at him. He made his words less clipped around the edges. “The other thing can wait, this is all... set-up, and then I need to do some configuration stuff. When it’s done I might be able to figure out the Thanos data, and that needs doing before anything else...”

“The other thing can’t wait.”

“Maybe it should anyway.”

Steve looked at him for a few seconds. Then he said, “Natasha, will you give us a minute?” and took hold of Tony’s elbow, steering him toward the elevator.

They got off on one of the ‘temporary residential’ floors, which were usually set aside for agents and scientists working too much overtime. Steve picked the first unoccupied door, flipped the sign to show it was claimed, and led Tony inside. It was exactly the same as every other room on the level: one twin bed, a nightstand with a toothbrush and a tube of toothpaste set in a glass, and a security feed with a noticeable warning sign and a reassurance that it was audio-only. Steve gestured at it, and with a thought, Tony grabbed it and every other pickup in range, double-checked that there were no living eavesdroppers nearby, and swathed them in a cocoon of secrecy. He gave Steve a nod.

“What happened with extremis?” Steve asked bluntly.

“It was—” Tony stopped, the words harder than they should have been. It was just an error report. Just errors. “There were errors. I think—Rudolph—he—fucked something up. I’m working on it. I can keep them contained.”

“Medical’s opinion is that you had a panic attack.”

“You try being locked in a room with him and see how great you do,” Tony snapped, which was a stupid thing to say because Steve had been picking fights out of his weight-class since he’d been a five-foot-tiny asthmatic with a bum leg. “It was—he got in my head.”

“He got in Clint’s head.”

“I am not having a heart-to-heart with Clint about this. He scrambled some programming, they’re bugs, I’m fixing it. I’d fix it faster if you let me work on it.”

Steve held up a hand. “Alright. Fine. Here’s what I wrote for the debrief.”

It took Steve about a quarter-hour to recite the entire thing—all of it, because Tony sometimes forgot how good Steve’s memory was. _Just hope he really does remember everything he said._ When Steve was done, Tony said, “You didn’t tell Fury anything about...” He couldn’t quite make himself say it; he gestured awkwardly at his head instead.

“No,” said Steve firmly. Or—was it? Tony played back the memory file—had he said it too quickly? _No, damn it. If he’d told Fury, he’d tell me he had. It’s Steve._

But Fury had agreed to releasing Tony to Avengers’ custody because Steve had said he’d keep Tony in line—had put himself out there, and after their fight in Maklu Steve _had_ to know that he had no guarantee except—and Fury _believed_ Steve, or Steve thought he did, but Fury didn’t do anything without a fall-back plan—

Would Steve—

He couldn’t think about it. Poking too near the thought made warning static hiss louder in his head.

“And you still haven’t told him about the Soul Gem,” he said instead. “From your... previous adventure.”

Steve shook his head. “It’s out of reach now anyway.”

“If it wasn’t captured by Thanos.” That made Steve look vaguely queasy, so Tony shoved off of the wall he was leaning on and said, “You’re making my eyes hurt. Get some sleep before you fall over, I’m sure everybody’ll want you for something in a few more hours.”

Steve grimaced, and eyed the bed with something halfway between resignation and longing. “That’s true.”

“Uh-huh.”

As Tony turned to go, however, Steve asked, “Tony—are you okay?”

_He was in my head._

_He knows—_

“I’m fine, Cap,” Tony said, and let himself out.

A suited SHIELD agent had materialized at the end of the hallway in front of the elevators; Tony eyed him, but the man didn’t move when he pushed the down button. When the elevator arrived the agent got on behind him. Tony eyed him again, then gave up and ignored him. Camera feeds showed that his workroom-to-be was still full of techs, so he pushed the button for the lowest sub-basement instead, which was also full of techs, all busy working on the chamber for the portal-device, but had the notable advantage of being where Bruce was.

 _Chamber_ was the right word: walls were being knocked down and support beams were being re-worked to get something large and cleared enough. Tony took a look around, allowed the agent to dog his heels, and then went to find Bruce’s lab before anyone could look up and recognize him. It was a decent lab, he thought, evaluating it from the doorway—his watcher oh-so-casually hung around a bit further down the hall. There were still things being installed, but the basics were there—and all the biological stuff for Bruce: fridges and ovens and all the biological reagents a man could dream of. It even had a massive equipment door that, according to the specs Tony pulled up, was designed to open automatically in the event of a Hulk-out and lead straight up and outside to a walled-in, no-access park. Too small an area to actually get the Hulk to _stay_ there if he was really pissed, Tony noted, but it was a start. A better start would have been if they’d realized they didn’t need it.

“Well, you look just as green as the last time I saw you.”

Bruce’s turned quickly, his attention snapping to him. “Tony.”

“I. Uh. I’m gonna sound like a dick if I say ‘long time, no see,’ right?”

“Just a... yeah, a lot,” Bruce agreed.  

“A lot of dick? Bruce, I had no idea.”

“Tony.” Bruce’s eyes were brown. Brown was a good sign. “Please don’t take this the wrong way—I’m glad you’re alive. Really glad. But... I think you should go away.”

“Oh,” said Tony. “Okay. I can... do that. Uh—how far...?”

“Just... please stay away from my lab.”

_Can’t say you didn’t have that coming._

Tony went.

There was no point in wandering the halls; he was restless, but he wasn’t caged. If he wanted to leave, he could leave. The agent watching him would pose no challenge. Sure, he could do with a fresher arc reactor, but he still had the one that he’d built for Steve stuck away in the subspace pocket—accessible once again, now that he had the armour back. But for all that he felt restless, there just... didn’t seem to be much of a point in going.

He sure as hell didn’t want to go back to the room where Loki had pinned him to the wall, though. Maybe he could grab a spare room next to Steve’s.

_Right._

“Fuck,” he mumbled, pushing the heel of his palm against his forehead.

He went back to the lab they were clearing out for him. It was bare-bones, a pitiful set-up more like an office than any lab worth the name. The main feature was the processing suite he’d brought from Oregon, the container for which was still getting bolted to the floor—useless, he could do _that_ with extremis. 

“Out, just—get out,” he told the two techs still there. “No, now. No, no arguing. Go.”

He practically had to shut the door in their faces to cut them off, finally. When had random people started _arguing_ with him all the time? It used to be that only Pepper, Rhodey, or random members of the press would argue with him. SHIELD...

_None of this matters._

The processing centre loomed before him. He reached out a hand toward it, letting extremis twine down around his wrist to form a hard-wire connection. Thinking became easier, faster.

_The only objective is to confirm if Thanos is out there. Find out how much Loki was lying. Nothing else matters._

_...yeah, tell yourself that enough and maybe you’ll believe it._

He wasn’t starting from scratch. Some part of Thanos had been _there_ , when he’d been lying in the dust where Tripitaka had dropped him, after—

_no_

A tiny bit of Thanos. He was certain of that much, even as out of it as he had been. The smallest piece—but it definitely had been _there._ Small measurements; measurements from a point, but a point was a place to start. Astrophysicists measured the universe from Earth, across distances that reduced Earth to a point, itself.

Astrophysicists could use red or blue shift to determine relative velocity. The frequency of the universe showed its shape. Look out into space and look back into time, but inter-multiversal portals used eleven dimensions, not four, and some of them curled; time couldn’t be put on the other side of an equation from space and solved so easily, and all his experiences with alien gods had proven that over and over. But the principle had to remain the same: the thing looked through gave just as much information as the thing looked _at_ , because they couldn’t be separated; they were one and the same. He knew his own point of view and he knew what his own point of view did when he looked at Thanos; he knew where and when he'd looked. If only he could fit the pieces together, he should have everything he needed... 

“You!” cried a loud, angry voice, and his concentration shattered as the door slammed open, bouncing off of the stopper. Threat assessment algorithms hiccupped with a processing error and he had repulsors formed on his palms, hands swinging up, before—

Target ID: Jane_Foster

Tony turned the movement into crossing his arms across his chest instead, hands clenched into fists.

Foster had jumped back, probably surprised at how fast he’d turned—

penalty for regicide is death.” 

She rallied fast, though, stalking forward again. He stumbled backward against the server bank and then sidestepped as she actually shook a fist at him—tiny woman, so non-threatening it should have been ridiculous, he could stop her easy as breathing—

bone crunched beneath his weight before he could brake, so light that he barely felt it through the suit. He’d hit 

He retreated back another step instead, frantically sorting through stacks to try and stop the memory-viewer from misfiring again. He didn’t want to see that. “Uh. Me?”

“You. STOLE. My work!” she snarled.

“Ah. Um.” He was breathing—fuck, he was breathing too fast. Funny. He’d just been thinking about time dilation. He synced his breathing to his internal clock and tried to ignore the oxygen deficiency flags that popped up. There wasn’t actually anything wrong with the O2 levels in this room. There was nothing wrong.

“You think I don’t recognize this?” She shook a sheaf of papers at him—printed out, yup, that was part of the instructions for the portal device. “Half of this is _mine!”_

“I know?” Actually, only about a third of it was hers—hers and Selvig’s; he wasn’t quite sure who’d done what to get that far. It wasn’t their fault that they hadn’t gotten the sneak-previews he had. The second half was a mix of Asgardian and Makluan, he didn’t know who’d done what there, either. He’d had to work out the bridging bits through the middle himself. 

“You stole my work and put your own goddamned name on it!”

It was a list of instructions, not _The Astrophysical Journal_ , christ—“I didn’t put my name on anything—I don’t think I even _have_ a name to put on anything—” It wasn't a goddamned patent, nobody’s name was on anything—

“My entire life my theories have been viewed as crackpot and when they start becoming provable you come here and you put it forward like it’s your own! _You_ say it’s yours and do you think anyone will think it might be _mine?_ No!”

His back hit the wall. “You want it, it’s yours! Whatever you want me to say, Jesus.”

“It’s mine,” said Foster, and glared at him again.

“All yours,” said Tony fervently.

“You put my name on it.”

Easy enough to alter the electronic copy—he clipped in a foreword, _Half of this is Foster’s. Ask her which half_ —“Done.”

The fist turned into a pointing finger jabbing at his chest. “And I _want_. _Your. Results.”_

“Already in there—”

“Your data!” Foster cried, throwing up her hands. One page slipped loose and slid to the floor; she didn’t seem to notice. “Measurements, oh my god, you are the first human being from this earth who has travelled to another planet and you’ve done it _multiple times_ , you _wear_ a giant computer, I know you have measurements! _Give me your measurements._ ”

“Christ, _okay,_ ” said Tony and

The other was the woman still making noises—but her chest wasn’t moving right; one side of it would move up while the other side went down. “Shit, shit, shit—flail chest,” and

Foster glared at him for a second longer, made a noise that sounded more like frustration than triumph, and stalked out.

Two heat signs moving quickly through different hallways toward him. He tore seat off a chair, and the bottom off of the cushion, pressing it against the woman’s side and putting her arms around it. Blood bubbled around her lips.

_“Mr. Stark, I am taking over control of the suit.”_ His limbs were locked up; he couldn’t twitch a finger.

“Nononononono—”

Tony gasped, and sight snapped back—his hands, pressed against the floor tiles. Pressure against his knees and toes—he was on hands and knees, bowed over. His internal clock chimed an alert—its reading was one-point-five-three seconds behind the GPS clock. His memory log jumped from standing to kneeling without break; he’d stopped recording as he’d fallen.

He synced himself to the GPS and shoved the log into the proper location. Black space opened between where memory ended and where it began again. Nothing there.

“Fuck,” he said, and it came out more like a sob.


	5. Shield and Sword: 1.5

Tony dreamed of sorting data. Or maybe it was that he sorted data while dreaming. Maybe he wasn’t dreaming at all. Everything had gone hazy, distant. The room around him stretched out in that warped, strange way that was so unremarkable for it being a dream, but it might just be due to the problems in his sensory modules. He combed through them languidly, detangling code with the half of his attention that wasn’t focused on sorting data into something readable, something understandable by someone who didn’t have multi-core quantum processors by which to keep track of many trains of thought at once.

Debugging himself while dreaming, he acknowledged, was possibly not the wisest course of action, but, like in any dream, this did not seem of great concern, until—

High-order decision relays enabled. 

His eyes blinked open. Data flooded in from the outside: cameras, phones, wireless, wired. The data that he’d been setting onto a drive for Bruce halted in its flow. Debugging stopped.

After a moment, Tony started it again. It had already found more errors, new ones developing where his prior scan had come up clean, including a truckload that had spawned in his recall algorithms. So. Not just a problem with his sensor relays. There wasn’t any sign of Loki’s program, either. _Damn it_.

The various drives he’d created, facsimiles of USBs made from extremis, were clutched in his hand. He made a face at them. Had he actually fallen asleep while making these? He checked the logs. It wasn’t quite like sleep, but... close enough, some kind of fugue state, sitting on the floor propped up against the cabinet for hours. Hours in which no progress had been made on the Thanos problem. _Damn it!_

At least the drives were more or less complete. He could enlist Bruce’s help. But Bruce had asked him to stay away...

Tony’s awareness of Steve pinged him as being back in DC, but SHIELD wouldn’t have left him without an Avenger guard, and he didn’t think Bruce counted. There would be another Avenger on base. Cameras yielded up the whole of the installation at once, data for a search subroutine—and informative, besides. He had to hand it to SHIELD efficiency: the labs now looked more like labs instead of interrogation rooms, upgraded shielding was nearly complete on the giant massive underground room needed for the portal generator, and—he scrolled through invoices—everything else was on-order or already delivered. Half of his storage-cube-slash-portable-fabricator had been hooked up, beginning to manufacture the panels that would be needed in such quantity for the portal device. At least... _that_ portal device. Tony looked down at hands, at the extremis wrapped around his forearms—and then he pulled himself to his feet and called Natasha. He was even nice enough to identify himself to her caller ID.

 _“Hey,”_ she answered the phone. Through the commissary security cameras in the lower commissary, he could see that she was sitting at a table with Clint; the pair of them were perusing tablets that didn’t reflect properly to the cameras. Huh. _That_ had to be intentional. He reached out through the wires towards them, but extremis couldn’t get a lock on their devices. Either they were well-shielded or extremely low-tech, or both. He’d have to look into how. _“You rejoining the land of the living?”_

_“I never actually left it, you do realize?”_

_“It’s a figure of speech. But if you’re going to lock everybody out of your lab you need to leave the cameras running. Do it again while Steve’s not here, and Hill will knock down your door with a battering ram.”_

_“C4’s more her style,”_ Clint said on the cameras.

 _“Duly noted.”_ He decided not to mention that it had been unintentional. _“Speaking of explosive tempers, I have a thing I, ah, need Bruce to take a look at.”_

_“Well, this is very high school. Clint and I are in the commissary. You should come join us.”_

_“...You also realize I already know that, right?”_

Clint looked up at one of the cameras and mouthed, _‘Stop being a creepy stalker.’_

Tony mentally hung up, and closed his connections to the bulk of the cameras. Outside his door, a plain-clothes agent lingered, although the guy couldn’t have been considered alert—he was going through inventories on a tablet. He looked up when the door opened, and when Tony stepped out, he fell into step behind him without shutting the tablet down.

Briefly, Tony contemplated turning on the ICG and making a break for it. Reality unhelpfully informed him that he’d need a new arc reactor. A better one. And there were refinements on the ICG itself waiting for him in the portable fab unit... time to go show SHIELD what else his mobile factory could produce.

_...some of it, anyway._

_Coffee first._

The hallways were more crowded today, but everyone got out of his way in a hurry: something had broken his anonymity. He stuck his hands in his pockets and tried not to think about it. Everybody had _always_ gotten out of his way—maybe not with those looks on their faces, but that was their problem.

Clint waved him over when he entered. Natasha was sitting opposite to Clint, so that between them they could see all the doors, sight-lines uninterrupted by any of the concrete support pillars that dotted the commissary. _Spies._ They had their bulky, secured tablets turned off. Natasha had a paper file beneath hers, but—Tony ran through camera records—she’d never opened it while at the table, or while on SHIELD premises. He could ask, but what would be the point?

The commissary was two-point-three decibels quieter than it than it had been before he’d entered. Yeah, he’d been noticed, alright.

“Here,” said Natasha, pushing over a bowl of sliced fruit. Tony regarded it dubiously. There were strawberries. “Did you finish sorting out your code problems?”

“Is everyone going to ask me that?”

“Fury wants to debrief you.”

“The last time you and Fury debriefed me it involved stabbing.”

“Stabbing to save your life,” said Clint, gesturing with a fork. “Think of it like acupuncture.”

“We’d like not to have to reboot the base while we’re at it,” said Natasha.

“That was—that was a one-time thing, there were extraneous circumstances.” _I hope._ “I don’t know why you need a debrief when I _actually_ filed a report for once, it’s on the servers.”

“We can learn more from questioning someone then we can from reading their report.”

He stared at her, wishing he could see inside her head. Sadly, extremis didn’t give him x-ray vision. Or, well, it did, sort of, but he’d have to produce some x-ray radiation to see by, and that would be absolutely pointless considering that the brain was all soft tissue anyway, and—this whole line of thought was idiotic. He cut it off. “That’s creepy.”

“You unleashed the zombie apocalypse, you’re not allowed to tell anyone else they’re being creepy,” said Clint.

Well, he had—

If—

“Clint,” said Natasha.

_stop_

Time sync error: 0.283

_sync_

“Not an apocalypse if the world didn’t end,” said Tony, smiling tightly. He dropped the thumb-drives on the table. “Although I guess you can pin that one on me, too. Mind giving these to Bruce for me? He might have better luck with it.”

Natasha and Clint exchanged a glance, one of those _I’ve worked with you for too long_ looks that conveyed yet more information that Tony couldn’t properly read. Then Natasha shrugged and said, “Sure. Nothing better to do than play messenger.”

“You really will take any excuse to avoid the Pentagon,” said Clint, making a face.

“The last two times I was there somebody tried to shoot me.”

“And how many people did you try to shoot?”

“Do or do not, there is no try.”

“Am I allowed to say _that’s_ creepy?” Tony asked Clint.

“You should see her Vader impression.” Clint leaned back in his chair, elbows on the plastic armrests, flipping the tablet over and over in his hands. “Come spar with us.”

leg sweeping out his own. He hit the ground and rolled with it, trying to roll desperately away, but he’d never been a match for 

_no_

“If this was the last birthday party you were going to have, what would you do?” 

“I would do whatever I wanted to do... with whomever I wanted to do it with.” 

“Aren’t you supposed to be spying on somebody somewhere?” Tony asked, indicating the tablets with a glance and a raised eyebrow.

“We do get leave,” said Natasha, instead of taking the rejoinder he’d expected. Was she going to be coy about it? “I’ve been undercover the last two months, I’ll take my downtime, thank you.”

He squeezed his eyes shut and then looked at her straight on. In infrared, she burned slightly cooler than human average—still within two standard deviations. Clint was hotter. _Let’s never say that again_ “ _What_ are you doing?”

She raised an eyebrow, but didn’t do him the disservice of pretending she didn’t know what he was talking about. “I’m trying to get you to see me as a person, not an obstacle.”

And she told him right out? ...Was that another layer of manipulation? Of course it was. “I do. Uh, a very dangerous—person.”

“Steve told us about the other world. The other me. I’m not her.” She arched an eyebrow at him. “I thought we used to get along.”

“I went for coffee with you.” Danger, danger Will Robinson—but if she was choosing to be direct then how could he meet her on that ground—

"But you’re not constantly twitching away from Clint,” she said, direct, direct, and leaned into his space—

.”nize a leashrecog when I see one. ingenious rkkkkkkk

“Thank you... for your cooperation.” 

Tony bit out a smile that he knew wouldn’t reach his eyes and held himself where he was through pure, terrified force of will— _one moment more just one moment more_ —long enough, just, to arrest the initial flinch. “Wouldn’t do me any good, right, to get to a _distance_.” He flicked his eyes toward Clint, and then, before his skin could crawl off his body, he shoved himself up and to his feet, springing up with the abandon of eccentricity, wealth and genius. Errors spit out garbage data, turning sight into static for  0.034 seconds before he dumped the top half of the register and rebooted the sensor processing nodes. He stuffed his hands in his pockets. “Well, it’s been fun, but I’ve got homework.”

“And I’ve got leave,” said Natasha, scooping the drives from the table. The downward tug of her mouth indicated hurt. His heart hammered in his chest—no. Garbage data. He cleared it and reset the debugger to work from the beginning, again.

Fucking hell, he was fucked if he couldn’t figure out where this was coming from.

“And I’ve got a better idea,” drawled Clint, standing slower than either of them. His eyes lingered on Natasha as she walked away—back, not rear, well-done, Clint. If he was worried there wasn’t any sign of it, and maybe—but, no, that wasn’t how Clint _operated_ , was it? If Clint wanted to find out secrets—

_Oh, that’s why._

Clint turned back to Tony. “Everybody wants to know what you have in that weird _factory_ of yours. Gonna pull back the curtain?”

“I already did. For chrissakes, I wrote a fucking manual.”

“For less than half of it. Come on, do me a favour. The tech squad gets any more insistent about taking the thing apart, they’ll be sending assassins after me.” Clint appeared to ponder this. “Or they’ll send Bruce. He isn’t talking, but I _know_ he’d like to know what you have in there.”

That was transparent. Obvious. As deliberately as Natasha’s? Tony wanted to rub at his face, he wanted more coffee—everybody in the commissary was looking-not-looking at them and in the back of his head a string of code gave its last gasp and unravelled.

“Yeah, fine.” He turned and made for the exit. Clint, shorter now than he was— _ahaha_ —matched his stride easily and walked beside him, so that the only person following _after_ him was the be-suited agent.

Upgrades to the fabricator had finished last night, and it had started pumping out panels for the portal device this morning. Of course, the panels were easy to make, comparatively. Raw stock for some of the other things he had in mind was low, waiting on SHIELD to finish shipping in certain components. But he had enough to begin with, and the fabricator had begun work immediately.

The fabricator itself had been installed underground, in a cement-and-lead shielded bunker surrounded by magnetic shielding, too, just to top it off. What, did they think it fabricated extremis? Well, to be fair, it did—or rather, it contained extremis, since that had been the easiest way to connect and run the entire thing, and extremis was self-replicating. Hansen had seen to that. Tony tapped into the shielding systems as they were waved through the check-point, ensuring that he had an opening, so that by the time they stepped past the boundary line it couldn't entirely cut him off.

Techs, clustered about the thing like cockroaches, all looked up at their approach—“Out,” Tony barked, “Everybody out.” Over his shoulder he jabbed a thumb at his follower. “Him too.”

“Now _I’m_ curious,” said Clint, _sotto-voice_ , but he raised both his hand and his voice, circling the former around in the universal signal for _round this up_ and calling, “Move it, people!”

Tony's bypass let him pick up radio chatter outside the shielded area—“Somebody get me a sitrep on what the hell they’re doing.” Against the stream of dispirited techs heading for the doors, one young woman sauntered back the other way.

“Yo. Boss wants to know what the hell you’re doing,” she told Clint cheerfully.

“What are we doing?” Clint asked Tony.

Tony flicked his fingers at the girl. “Bye.”

She raised an unimpressed eyebrow at him.

Her ID badge had flipped face-down, but a facial recognition scan across the SHIELD database yielded up who she was: Lewis, Darcy, assigned to Dr. Jane Foster. Tony felt himself freeze.

“The magician doesn’t want to reveal his tricks,” Clint intoned, and he nodded his head toward the door. Aggravatingly, _that_ seemed to work: Lewis didn’t look any more impressed than she had with Tony, but at least she went away. Clint wandered off to forcibly evict a pair of scientists who had yet to start moving on their own, and Tony shoved his hands in his pockets, watching.

It didn’t really matter where he was for this.

The last scientists were pushed over the threshold, and held back by agents while the vault doors closed... closing them out, not closing Tony and Clint in. A thought disabled the internal security cameras, and then came the moment of truth.

Another thought opened a panel on the side of the fabricator, folding it out to reveal a box—detachable crate, really. Tony thought extremis into heavier patterns around him, then dug armoured fingers into the grips on the crate's side and wrestled it down onto the floor. The crate itself was heavily shielded: the contents weren't particularly explosive, but the energy signature would certainly be eye-catching. The shielding around the room, for all that it was based on his own stolen designs, was sub-par. Tony kicked his own defences into high-gear, ignoring the power drain.

After all, it shortly wasn’t going to matter anymore.

The top of the crate lifted off, unsealing with a hiss, revealing twelve slots packed far apart, further than they needed to be. The crate was designed to hold the older versions: complicated, toxic, and liable to explode with the force of a small nuclear bomb if you tampered with them right. Back when he’d been in the internet, he’d used this lab to fabricate a couple dozen of them. He didn't have the materials on-hand to duplicate that feat now, so all but one of the slots was empty. 

“That powers this thing?” Clint asked, as Tony picked up the reactor between thumb and forefinger, easing it from the case with undue care. He could jump up and down on this one in jetboots and not make a dent. Still, he felt reluctant to scuff it quite so soon.

“Not exactly.”

Extremis melted away from his hands as he turned the reactor over, inspecting it. From the front, the new reactor closely resembled an arc reactor, but it was only a centimetre thick; arc reactors needed the base to stabilize the rings, but Makluan science had solved that problem eons ago. Without the library nexus still in his head he didn’t still understand much of the history required to arrive at the principles for this new version—but he sure as hell knew how to use the conclusions.

This new version was shinier, sleeker, and better in every conceivable way. 

Clint wasn’t stupid, even if he wasn’t a scientist. “You built an arc reactor factory.”

“Yup.”

“...That doesn’t look like the reactors I’ve seen.”

“It would’ve taken me decades to get this far on my own,” said Tony quietly. “It’s not, strictly speaking, an _arc_ reactor.” That would be like calling a modern dam a water-mill... true, but not true.

“Then what is it?”

“Better.” He exhaled. “This could run the east coast for a year.”

“Hey, you already did zombies. Leave the economy alone.”

This _would_ be a crisis. Technology was going to change the Earth again, just like it always had. Maybe he’d never had enough care for what he built. It was too late to worry now: Earth didn’t have a choice in this. Upgrade, or be destroyed sooner rather than later.

_Fuck it, not like it’ll matter in the end_

The nice thing about wearing extremis was that there was no need for fumbling at zippers or buttons— _I used to care about that more_ —it just flowed out of the way so that he could pull the old arc reactor. Thick lines of nanites connected the ICG on the bottom to the new reactor, so that he could switch it over without interrupting the power. When he was done, the cabling flowed into the shape he needed it, and he stuck the new reactor in his chest. The old one glowed gently in his hand. It had been forged with a priceless amount of natural vibranium, and now it was obsolete.

He could recycle the vibranium, at least. There was possibly enough unpolluted vibranium left in the old reactors to make a start on replacing the ring he'd taken from Steve’s shield. It might earn him brownie points.  

“There’s twelve slots in here,” Clint pointed out.

“Uh-huh.” Tony pushed the lid down again, extremis engaged the locks, and he lifted it back up to the module, setting it into place and pushing it back into the fab unit. Locks engaged; safety features, to prevent radiation contamination, hummed back to life. “You’ve got the list of raw materials.”

“You’re going to have to watch them constantly or somebody’s going to take one apart.” Clint crossed his arms. “I’m _not_ spending my time scientist-wrangling for you.”

“Didn’t ask you to.” Tony shrugged. The armour faded back into heavy clothing.

“They already want to take _this_ thing apart.” Clint flapped an arm at the fabricator.

“Oh, I’m sure you won’t let them kill the golden goose _that_ easy,” Tony breathed, and froze.

_why did I say that_

Clint was watching him. Warily. No glint of blue in his eyes, but SHIELD had its own cloaking tech, enough to cover the face—

_STOP it what the hell am I thinking_

“I’m not touching that one,” Clint informed him.

He wanted to bury his face in his hands. “Right. Sorry.” Or disappear. The desire became stronger with the knowledge that he _could_ , now. The Makluan reactor would power the east coast for a year... or the ICG for fifty lifetimes. It pounded through his head, closing his throat, disrupting the feeds. _no, damnit_ There was something else he needed to check on, here. Other things—in the fabricator—

“Hey. Look, Tony—maybe you should sit down—”

“I’m done here,” he snapped, and kicked the ICG into life. It hummed in his ears—was it audible to Clint? Clint didn’t look away, and his gaze followed Tony, slightly unfocused, as Tony stepped backward. Sound. Shit. Of course. He needed to calibrate—extremis could calculate the exact amount of force of each footstep, dampen the impact and modulate the noise to nothing—but the code for it slipped away from him. Fuck.

They were all so fucking screwed.

The armour enfolded him, a protective embrace that was nothing more than a lie—anybody could strip him out of it with the right code key. With the right code key stripping him of it wasn’t even _needed_. He stalked away, slamming the doors open with the mental equivalent of a drunken flail—fuck these errors. He needed to diagnose it, figure out what the hell Loki’s program had done to him—he needed to—to—

Time sync error: 132.981

_sync_

_where the hell am I?_

His... lab. Door locked. Processor bay in front of him, humming ominously with signals that only he could hear. He was... sitting in a chair? Where the hell had the chair come from? There hadn’t been one here before—or computer monitors. Why did he need those?

The door was locked. The door was definitely locked.

Slowly, methodically, he forced his attention back to the debugging program—and then again, when it slipped, and again—and again—

It felt like ages before false low-oxygen warnings stopped flaring up at him, and he recovered enough of his brain to realize that he ought to hardwire into the extremis cabinet. It took another minute for him to actually do it, and then his brain cleared enough that he could be disgusted at himself for not hooking up sooner.  

But the cabinet didn’t fix it. The source of the errors remained elusive, and static kept creeping into his brain, until finally his proximity sensors pinged him with an external interruption that fried his concentration completely. Tony opened his eyes, rubbed his face, and checked the feeds. The timestamp had progressed by seven hours; he checked it against the GPS clock and corrected the difference that had accumulated. 

Video feeds showed Bruce was outside his door. Bruce? Several thousand lines of data were added to the error log in a millisecond and wiped out. He squashed the bit of intuition that accompanied _that_ and left it for later. Right now Bruce was about to knock on his door. Bruce was about to knock on his door, Bruce had told him to leave but here he was—

The knock came. Tony shut down the log immediately, standing—then opened it up again. Right. He was just in the middle of working, Bruce looked nervous in the sensors, he should be cool, no big deal—he shut the log again, opened up a half-dozen windows to random sites on the Internet, and threw them up on the desktop monitors. Right. He should answer the door.

Bruce was standing with his hand raised to knock on the door again when Tony opened the door. “Uh.”

“Bruce!” Tony said brightly. “Long time no see!”

_SHIT, why did I just say that?_

“Uh-huh,” Bruce muttered, looking down and pushing his glasses up his nose.

“I mean, here I was, just thinking of your math, and here you are.” Tony seized the momentum before it could run away on him completely. “Uh. Come in, to my humble abode—I’m sure if I don’t have a math problem you’ll like, I can think of one.” He kicked the door wider, standing back and waving at the... rather dark interior. _Lights on._ The lights went on. _Better._

“Oh, you’ve given me plenty,” said Bruce wryly, and Tony found himself suppressing another wince. _Ouch, Bruce._ “Uh. Check my math?” He held up the papers he was clutching.

This was good, this was a peace-offering. Tony took the papers, glancing through them. Extremis committed them to memory immediately, but he found himself loath to just hand them back. And it would probably be rude. “Sure. Anytime, I’ll... get right on this. Uh. You’re probably really busy, but if you wanted to see—”

“No,” Bruce interrupted hastily, and then made a face. Tony couldn’t hide the wince this time.

_Ow._

“I mean,” Bruce said, more gently, “I’m sure you have... extremis means you don’t really need somebody to check your math anymore, does it?”

The end product? Not so much—not as long as he ran the debugger at a fast enough repeat rate. Didn’t mean he didn’t need inspiration, as his ongoing problems were so aptly proving. Tony fixed a smile on his face. “Well, if you wanted to toss around ideas...”

“Sure,” Bruce said, but he was already turning awkwardly away. “Maybe later, Natasha gave me your drives. Uh. Lemme know what you think, okay?”

Right. Okay. Maybe he was fucked in the head, but he could figure out three refusals in a row. _Sure. Still good that he came at all. Right?_ “Yeah, sure.”

Bruce began to shuffle away. Tony let the door thunk closed, and resisted the urge to bang his head against it.

He’d been getting nowhere sorting out his own head, and even more nowhere with the Thanos problem whenever he turned to that; a break was in order. Shelving both let him turn all that space in his head over to the question of Bruce’s... concession. It was at least something. Math. Right. Probably non-essential, but, fuck it, it was Bruce, maybe it _was_ essential, maybe it was the answer to the whole damn problem. He tossed the papers on the bench and leaned back in his chair, letting his hand drop close enough to the cabinet that he could hook it again without thinning the cable.

Bruce hadn’t been kidding when he’d said _math_ —he wasn’t fucking around, here. There was no physics to be seen; he dove straight into the elementary mathematics and never really surfaced, coming to a number of brilliant conclusions, but not any that, as far as Tony could see, had any practical purpose: they all focused on non-infinite _n-_ dimensional geometry, which would point at real, practical purposes, but there was nothing from his proofs that jumped out as being a part of the enormous set of rules for calculating inter-reality portals, or even simpler inter-realm portals. What the heck was he aiming at? Why had he given this to Tony? He sat up, and spread the pages out on the table, putting them in order so that he could see them all at once. Sure, he could call them all up in his head... but this was more concrete.

_that’s a really stupid thought_

Maybe he just wanted to see the proof that Bruce had given him the first copy, his original hand-written notes. Something to be trusted with.

They took up the entire table, and then there was still a stack left over. Occasionally things were scribbled out, and Tony could see—or rather, predict, with a different kind of mathematics—where entire pages had been discarded, either totally written off or thrown out to be rewritten in a form that made each theory progress. How long had Bruce been working on this? Was it recent?

Context. He needed context. Part of his mind he sent jumping between satellites, hijacking signals and cracking open databases that should have been secure, but he knew his own designs better than he knew the inside of his head. Sloppy, SHIELD. Security cameras in months past had recorded details, times, dates—Bruce had started working on this after reverse-engineering the Tower’s shielding. _doesn’t mean it’s related_

Maybe it was just a nice gesture.

All the math checked out, anyway. More than checked out; it was... beautiful, elegant. Tony could appreciate that. There was a certain charm to the often brutish mathematics of applied science, but Tony had favoured Fourier over Laplace as a child for a _reason_.

Something about this had to be related to the shielding. Had Bruce seen something? The first anti-Asgard shields that Tony had built had been based off of radiation, but when he’d gotten down into the series that really _worked_ , it had been based on travel: on higher dimensions and ways to bend them, and therefore things in them. There were ways to vanish from reality, from certain points of view, while actually being present all along. Most of it was based on Foster’s work. The much more advanced versions he’d taken from Maklu’s library had borne out certain assumptions, and then added a whole new set: rules of physics for which he didn’t understand the history. Rules that he could use... but they needed to fill in the gaps before they could go further. Was that what Bruce was trying to do? He seemed to be going about it damn obliquely, if so. It made Tony’s skin itch—

Or maybe that was something else.

_what the fuck is creeping me out_

He checked the security feeds around his own lab. Nothing of interest. The number of scientists brought in beneath SWORD’s umbrella was increasing rapidly, but the number of spies and soldiers was slower to grow. Bruce looked—actually, a whole lot more zen then he did at any comparable times in the last three days. Last three months. _well that’s my fault_

There wasn’t anything wrong with the math. He ran it, again and again, bounced it to a different processor suite and ran it again—there was nothing wrong with it. Bruce’s math was as deliberate as Bruce himself, an exact progression from point A to point B to point—

—except not exactly like that, because one of the bits theoretical proof _Tony_ had done in the last few months was to disprove the uniqueness of that—but that didn’t mean the link wasn’t valid, in any case, Bruce didn’t assume it. Even in that one proof where he approached only the non-trivial case—

Yet—

The room vanished entirely from before his eyes as he bulldozed through the SHIELD security banks. Proximity alarms would warn him of any danger—any _physical_ danger. Right now he needed all the visual sensor suites to process SHIELD’s records. Bruce’s discarded drafts—why did he do everything on paper? Just as well; SHIELD computers didn’t all have keyloggers. Most of the reams of notes were garbage, bullshit, the types of dead ends that you naturally ran into doing this sort of work, or various kinds of useless—the useless ones he followed, tugging at ideas. And then, down one road—two months ago, and Bruce had balled up the piece of paper and tossed it over Steve’s head to land in a trash bin in medical—Tony found what he was looking for. Dots connected in his head, and if he took some of Bruce’s theorems here and applied them a bit differently, he could follow them to... Euclid’s First Postulate.

Proven.

_eureka_

_i’m fucked_

“The line between point A and point B is unique,” he intoned, quietly, to himself. His sensor processors redistributed the task load; he let SHIELD’s records go. The equations for the proof needed no more than a fraction of his previous computing power for checking—and there had to be an error in there somewhere, because he’d _disproven_ that postulate himself two months ago.

Two proofs, identical base definitions—or rather, identical once Tony went back and reduced a bunch from the theory he’d cooked up—but their conclusions were contradicting. The base definitions had to be wrong, then. Proof by contradiction. But where? This was the most elementary kind of math; it didn’t _get_ any more basic than this. Where was the logical fallacy?

Maybe it was someplace he couldn’t see. Someplace entirely outside of the math. Bruce had joked that Tony didn’t need anyone to check his math, but his sensory suites were already throwing errors—he bumped the debugger up the priority list and set it to scan. There had to be something wrong.

His brain was falling apart.

_already knew that_

He wrenched himself out of the math, and scrabbled for something to distract himself. The first thing that came to hand, figuratively speaking, was an email inbox that somebody had created for him on SHIELD’s servers. Surprisingly, it wasn’t full of high-priority messages. Was SHIELD actually serious about not wanting to waste his time? Or had they hired him a PA when he wasn’t looking? Like—

Tony squashed that thought, too, and took a look at the first flagged message. It was from somebody named Ron Hatchet— _Dr. Ronald Hatchet, PhD, junior team-leader in the Astrophysics Division, assigned to SWORD 0 days ago_ according to SHIELD records.

It took him a few nanoseconds to parse the email; it took longer to check the attached data. Then the static rose up around him, and it was all he could do to keep it at bay.

 

* * *

 

When Steve made it out past the inner and middle cordon of security, he found Clint waiting for him. Dressed in civvies and sunglasses, Clint’d attracted his own pair of secret service agents who were none-too-subtly keeping an eye on him. If anyone else realized there was an Avenger hanging out at the Pentagon, they were far too professional to be awed.

“They need me back home?” Steve asked as he neared, and Clint shoved off of the wall.

“Nah. Just got itchy feet,” said Clint, which had to be the biggest lie Steve had heard all day, and he’d been mostly meeting with politicians. Steve walked faster. Clint looked relaxed on the surface, but Steve could read the minute cues in the way he slouched that hinted he was irritated, and probably wanted his bow back.

When they reached the privacy of the quinjet, Steve let himself stop and stare—because there was Natasha. “I thought you said you weren’t allowed in the Pentagon.”

“No, she just hates it here,” said Clint, sliding past him and into the pilot’s seat.

“I really do,” said Natasha, closing the hatch. She pulled out an AED, one with three more buttons than the one Steve had, and flicked it on. Instantly, Steve had a headache: the whine was even worse than normal. It could probably be heard by every dog in DC. In his left ear, his comm crackled with static.

“Sorry,” said Natasha, seeing his expression. “This is the high-power version. We need to talk about Tony.”

“What happened?”

“I dunno if you noticed, but he’s kind of fucked up in general,” Clint called back.

“Clint.”

“He handed over the data he had on Thanos this morning,” said Natasha. “The astrophysicists cracked it. According to them, Thanos causes a detectable warp in space-time and it is not only present pretty much _everywhere_ in the background, it’s definitely not just leftovers present. Something’s still actively generating it. Short version, they’re pretty sure Thanos is still around.”

Steve took a seat on the bench, hiding a wince. The AED felt like it was making pressure build up in his ears. “That’s... a bigger problem than Tony.”

“Yeah, considering Tony’s supposed to be our main weapons developer for this?” Clint stopped fiddling around in the cockpit and stepped back into the main cabin, leaning against the dividing wall. “Guy said he couldn’t figure out from the data if Thanos is still around or not, but a SHIELD team got it in less than two hours—not even Bruce or Foster, just their minions. Houston, we have a problem.”

“You think he’s lying.”

“Actually, I don’t,” said Natasha. “I think he’s panicking.”

“He definitely had another panic attack,” said Clint.

“The base?”

“Nah, the power stayed on, he just turned invisible and freaked the rest of us out instead,” said Clint, giving a one-shouldered shrug. “Then locked himself in his room for the rest of the day. Hell, I even managed to go egg Bruce into making peace with him, but nope, that lasted for all of five minutes, then he’s back to sitting there with metal tentacles fused into his skin. He’s probably still there. It’s not clear he even registers other people knocking on his door.”

“Enough about the tentacles. Seriously.” There was a bite to Natasha's tone that said she'd heard far too much about tentacles on their flight over here. 

“They’re creepy, Nat.”

“So... he’s panicking,” said Steve, trying to steer the conversation back on course.

“Panic makes it hard to think,” said Natasha. “He might just be sitting there not doing anything, or he might be trying and failing. Since he _did_ give the data to Bruce, I think it’s the latter.”

“Then he needs to see psych. Counselling, therapy—maybe medication.” Steve rubbed at his skull, just behind his ears, trying to relieve the pressure there. “Not like it’d be a first time for one of us.”

“Be a first time for Tony.”

“We have legal custody,” Steve said reluctantly.

“Yeah, that’s, uh, that’s not gonna help.”

Natasha held up a finger. “One: people only get out of therapy what they put into it.” She raised a second finger. “Two: whatever you left out of your report to Fury is going to get in the way.”

“What do you—” Steve started to protest, then gave it up and asked instead, “Why do you think it’ll get in the way?”

“You sold Fury on keeping Tony Stark in the middle of the most densely populated place in the US. The guy responsible for the Nanoplague, the guy who built at least two secret labs while being quote-unquote ‘in the internet’.” Being Clint, he added the finger quotes. “And who was self-admittedly insane for a while and then cured by a _wizard_.”

“You’re obviously omitting things from your reports—some events just don’t add up,” added Natasha. “Fury just said that he was certain Tony would listen to you. The Director’s a bit too optimistic sometimes, but I didn’t sign up for SHIELD because I thought he was an idiot. If the Hulk goes out of control, he could kill a lot of people. Tony, with extremis—he could kill _everyone_. Especially sitting where he is right now.”

“He wouldn’t do that.”

“Really? Because from what you _did_ report, he nearly did just that, trying to fix the Nanoplague before it ever happened. But now somehow you sold Fury on it.”

“I promised I’d stop him. And I will.” _I won’t let it get that far in the first place._

Which would be a damn sight easier if he didn’t have to spend so much time in DC.

“How?” asked Clint. “He kicked your ass the last time you disagreed, and you _said_ you don’t have any more of the Makluan whatever-it-was that shut him down.” He paused. “Which, uh, you’re a terrible liar, Steve. But he’s scared of you now? He’s been on edge, snapping at Natasha, snapping at me when he thinks I might see through him, figure out what he’s hiding—” Clint paused.

 _I didn’t tell Fury I’d use it,_ thought Steve, feeling ill. He couldn’t be sure if it was the AED or actual nausea. _I won’t. I shouldn’t have considered it, and I won’t ever consider it again—_

But had he _implied_ , by Fury’s twisted logic?

“Also there’s that look on your face,” finished Clint. His eyes were cool, sharp: self-imposed distance, to let him see the picture clearly. “So, yeah. We know you left shit out of your report, and we know some of that shit was whatever you’ve got over Tony that scares the crap out of him.”

“I said I would stop him,” said Steve, floundering. Trying to think. The headache was making it difficult. “I—” _I wouldn’t do it that way,_ he wanted to say, but a cold rush of realization washed through him: anything without certainty wouldn’t be acceptable to Fury. If he told them... would they tell Fury? “I didn’t say how.”

“Shutting down extremis wouldn’t scare him that bad,” said Natasha. “It wouldn’t make _you_ look this bad, either.” 

“That’s the headache from the damn AED,” said Steve, pointing at it. Removing his fingers from his skull made the inside-out pressure worse, and he winced. 

“Sorry. Look, we understand that this thing’s bad, Steve. Whatever it is. It’s also clearly needed. But you need to sit down with him and define exactly when and why you would use it, and _convince_ him you won’t use it for any other reason. Right now he’s panicking, he’s reverting to captive-behaviours, and ordering him into therapy isn’t going to do any good while he’s viewing his therapist as one of his captors, trying to get inside his head.”

“Not that psych can’t be damn annoying,” said Clint. “I won’t lie and say I haven’t ever played ‘em, everybody has. But there's a time to get the shrinks involved and we crossed it months ago.”

Guilt wormed through Steve’s stomach. He’d told Tony he hadn’t told Fury; he should have told him of his resolution regarding Makluan mantra. He hadn’t realized how Tony had seen it, that Tony would consider it a threat; he’d been too exhausted, wrung out physically and from the endless pitching of SWORD to suspicious parties—but that was no excuse.

  _...freedom from fear and want has been proclaimed as the highest aspiration of the common people..._

“Right,” said Steve, and he nodded at the AED. “Shut that thing down, and let’s get back to New York.”

Turning off the high-powered AED killed both the whine and his headache almost instantly, leaving him light-headed for the first few minutes of the flight. He forced himself to pull his thoughts together despite it. The gut instinct that he’d been working with—that using the headband would be heinous, that Tony hated Tripitaka, that they’d both thought he was scum and, beyond that, useless—wouldn’t be good enough to convince Tony, not if he thought he’d already been betrayed; Steve would need to pull it together into some sort of coherent, logical form. He was grateful Clint kept the flight subsonic. It game him time to think.

At the NYHQ, they landed inside one of the warehouses with retracting roofs. The hangers were bustling with activity, mostly concerned with SWORD resource runs—building inter-reality portals required materials that even SHIELD couldn’t simply wish up out of nowhere. Steve ducked through the industry, waving off Clint and Natasha when they made gestures querying about following him, and headed for one of the hallways over to the main building, where there were elevators leading down into the depths of the base.

Clint had said that Tony was ignoring knocks on his door, but when Steve raised his hand, the door slipped open before his knuckles could make contact. For a moment, he stood there, staring into the dark beyond. Then he stepped in, feeling to one side for a light switch as the door shut behind him, leaving him in near total darkness.

Overhead lights came on a moment later—and Tony stood up, from where he’d been sitting on the floor behind the desk, which was why Steve hadn’t been able to see him earlier. Thick, shiny-silver cables trailed from beneath his sleeves; as Steve watched, they detached, fell to the floor, and slithered back into the cabinet behind him.

Clint had a point about the tentacles, Steve thought.

“Hey,” Steve tried, going for casual. “So... I think I wasn’t really clear yesterday.” He took out his AED and flicked it on, stepping forward to leave it on the desk, in plain sight.

Tony flinched, almost managing to hide it by stuffing his hands in his pockets—but that just made him look hunched over, inward-drawn. For someone who had been unconscious as much as Tony had in the past few days, the bags under his eyes were far too deep, like bruises.

Steve took a breath. There was no other way to say this, no other way it should be said, than bluntly. “I am never, ever going to use the mantra against you.”

For a full five seconds, Tony gaped at him, blinking: too fast, Steve saw, and Tony’s breathing was too fast as well—signs of a panic attack, either on the way or already started. Clint was right. Natasha was right. He should have had this conversation days ago—he should never have given Tony reason to doubt in the first place, God forgive him for ever implying it, for ever _considering_ it. Steve shook his head. “I wished you’d never even mentioned it. That I’d never had to think about it. Well, I thought, even though I never should have, and now I’m never considering it again. I _will not_ use it.”

Tony's mouth worked a few times, before he managed to say, “But—you don’t even know what I could do. You thought I was going to—”

“I will try until the bitter end, but I won’t give up. When Tripitaka”—Tony actually _cringed_ at the name, and Steve winced—“he spent all his damn time thinking about the lesser of two evils and y’know what, I _won’t_. I’ll find another way.”

“I—” Tony stumbled backward, into the banks of servers, and Steve took a few steps forward, concerned about his ability to stay on his feet. Despite everything Steve was saying, Tony was just panicking faster—his eyes were darting about wildly, but seemed unable to actually land on Steve. He was shaking badly enough that he’d put out a hand onto the cabinet for support, and Steve didn’t think it would be enough. “I—”

“Tony?” Steve asked carefully. Was confronting it—making it worse, somehow? Steve’s presence didn’t seem to be helping—but he couldn’t leave him like this. Carefully, telegraphing his every move, Steve inched forward.

He was about halfway there when Tony abruptly sat down on the floor, burying his face in his hands, and made a noise somewhere between a laugh and a groan. “He knows,” Tony said, the words terse, shaking.

“Who does?” Steve asked, kneeling down to be at eye-level. Not that Tony was looking at him right now.

 _“Him,”_ Tony said, and there was only one person whom Tony spoke of with quite that level of both hatred and fear.

 _Shit_. Oh, Lord. Oh, Hell. No wonder Tony—oh, _Hell_. Steve reached out, putting a hand on Tony’s shoulder—Tony jerked away, but after a moment Steve wound up half holding him up, while Tony shook to pieces.

“Does he know how to use it, or just about it?”

“About it,” Tony managed. “I think. I can’t—it's magic. Picks things out of your head. Steve, I can’t. We’ve lost.”

If Loki didn’t know _how_ to use the headband against Tony, then there was still time. Opportunity. “Not yet.”

“No, Steve, I can’t—I can’t _think_.” He managed to look up at Steve for a moment before his gaze skittered away again, fear radiating off of him. “I can’t think, I can’t—useless, but I can’t—do this. Everything goes—errors.”

“Okay.” Steve made the decision in an instant. Maybe Fury would be pissed at him later; maybe Hill, maybe all of SHIELD. In the moment, it didn’t matter. Tony was falling apart right in front of him—it was the only decision he could make. “You don’t have to.” He eased himself down to sit beside Tony, draping an arm across his shoulders and pulling him in. “We’ll take it from here.”

“You don’t know,” Tony said, his voice rising in panic. “He’s not like—you haven’t seen—”

“I know,” said Steve firmly. “I know. He’s probably the worst foe Earth has ever faced. But we’ve got the brightest people in all Earth, and we’re making progress on reaching out to others. You catapulted Earth’s science ahead by decades and we’ve got everything you got in Maklu, elsewhere—you’ve done enough. You can stand down.”

“Please,” said Tony, curling against Steve’s side even as he shook. Steve wasn’t sure Tony even knew what he was asking for. His eyes were wide, unfocused, terrified.

“It’s okay,” Steve repeated. “You don’t have to. We’ve got this.”

He kept repeating himself, kept his arm around Tony’s shoulders, pulling him close until Tony’s shaking finally started to subside. But the thousand-yard stare was still there.

Steve settled in to wait, and started re-working plans in his head.


	6. Shield and Sword: 1.6

Boot @ 201402241543.493. Welcome back, Mr. Stark. 

Changelog summary:   
34 patches applied.   
88 corrupted files detected.   
88 files quarantined.   
2 root errors found. 

Had he just...?

Tony’s brain finished booting up, and helpfully queued memories clarified that yes, he had just freaked out so badly he’d auto-rebooted. The slower-booting sensory data—and that was seriously fucked, the sensory processing ought to be a hell of a lot faster to get up to speed than that no matter how many errors it was throwing—informed him that he was still in the lab, and cuddled up to Steve like Steve was... protecting him from a nervous breakdown.

_Aw, fuck._

This was... embarrassing. Humiliating. Yeah, humiliating was probably more accurate, here. He blinked, experimentally—everything seemed gummed up. He hadn’t actually been prepared for those patches to run, but apparently they’d done so as soon as his brain had checked out. Right. Because he’d had them set up to autofire, except he’d forgotten to get around to shutting down, because, of course, nervous breakdown.

“Back with me?” Steve said quietly.

He’d have shaken his head in disbelief, but that would have pushed his face further against Steve’s chest. Instead Tony sat up, being careful to _not_ do so as quickly as possible—because this was awkward, yes, but he didn’t need to make it any more awkward. Steve was tapping left-handed at his phone, but he withdrew his other arm from around Tony’s shoulders and _st—no, shit, I can’t keep—damnit._

He shouldn’t be missing the contact that much. What the hell was wrong with him?

“I’m not really sure how much you were processing just now,” Steve started carefully, and Tony interrupted him almost automatically.

“Yeah, sorry.”

“Not your fault. But I’ll repeat myself. Tony, I’m not using that mantra on you.”

He felt himself freeze. It was probably a good thing they were still sitting on the floor. That fucking paralyzing feeling was creeping up his spine again. But Steve was looking at him like he wanted him to say something, and he kind of owed Steve for... well, freaking out at him and then using him as a teddy bear, Jesus, so he managed to say, “Okay.”

“Also, you’re going to therapy twice a day until you actually believe me. Or you can let a psych in here, but you’re going to talk to a professional and not keep doing end-runs around ‘em.”

The thought-stopping paralysis seemed to be content with lingering at the base of his skull right now. Tony sighed. “Steve...”

“If you don’t want to talk to Dr. Kafka, you can see someone else. If you don’t like them—keep trying.” Steve shrugged. They were still close enough that Tony could feel the movement. It was hard not to lean into it. Steve radiated warmth like a space heater, and somehow, with that, a feeling of _safety_. Christ. What was he, a child?

Tony scrubbed at his face. The dull feeling was slow to fade—was that from the reboot, or from the fucking nervous breakdown? Or had the patches not applied properly—worse, had he miscoded them? His nerves jangled. _fuck_ “It’s not about belief, Steve. I—could have saved them. The people I got killed in Shenzhen. I know I could have.” _Keep telling yourself that..._ “But. Tripitaka—” His throat tried to close up on the name, and he had to cough. “If _you_ really thought otherwise, about the outcome—he was right. Using it.”

“Y’know, I hated those ethics questions,” Steve said thoughtfully. “One of the first psychs I saw, out of the ice—he kept tossing ‘em at me. I hated them—so damn frustrating. ‘Save a baby in a carriage, or a bus full of elderly people.’ Why was there never a chance to save both?”

“Sometimes there’s not a way out,” Tony parroted back at him.

“Yeah, that’s what I thought at the time. And sure, in the immediate moment, maybe it comes down to that. But if you start off convinced that’s where you’re going to end up... you miss things. Come on, you’re the one who told me about game theory and iterative trials. If Tripitaka hadn’t been such a scumbag, right from the beginning—would you have listened to him, at the end?”

Tripitaka—trying to picture Tripitaka as anything, anything but—

If he had—

But—

 _Fallacy._ He turned it over in his mind. Tried to evaluate it. But Tripitaka wasn’t an _expert_ —

Time-lines travelling at different rates, hook-ups to a world-net containing the knowledge of one of the most advanced civilizations in the multiverse...

No. He wasn’t wrong about this. He could have saved them, he _could have!_

_Stop fucking lying to yourself, you never had time to run the math properly._

And he hadn’t since—there was too much else to do, too much else to avoid, and why _bother_ , when it was all futile and thinking about it made his hands shake—

“No,” he croaked. “No...”

“Maybe,” said Steve, _damn him._ “Well, I’m gonna change it. We’ll find another way, between the two of us and the rest of the Avengers.”

Tony coughed, struggling to keep it from turning into hyperventilation. He won, after a moment too long. “And if I still disagree?”

“At least you’ll have all the information,” said Steve. He shrugged. “I figure I’ll at least have plenty of practice at using my best disappointed stare, because, uh. Until this is sorted out, I want you to stop working on the rest of it. No portal. No Thanos-killer.”

“What?”

“This isn’t about trust. Tony, I trust you—”

“You shouldn’t,” Tony muttered. He couldn’t meet Steve’s eyes.

“Well, I do. But working on this isn’t what’s needed right now. You need to get your own head in order—fix extremis, talk to the docs.”

How could this _not be about trust?_ It felt like a punch in the gut. “I—Steve, you can’t—” If he didn’t—if he couldn’t—it wasn’t even like Steve could enforce it, he did all his work in his head!

 _So successful I’ve been with it, too._ He hadn’t managed to work out how to detect Thanos, when a bunch of SHIELD’s painfully young post-docs had put it together within _hours_ ; he’d had it for days, and then they’d come along and just... figured it out. No wonder Steve had figured out there was something wrong with his brain.

_God, I’m getting old._

Getting old. Obsolete. Outdated. The fastest mind in humanity—presumably; maybe he’d have to hand the title to one of those kids—and he could barely keep up with what Loki had done to his head; he had no fucking idea how to deal with the _being_ that his sensors had registered. Steve was right that he needed to fix this, but he couldn’t just leave _everything_ to those kids, abandon the fight—

“I can stare at you in disappointment until you stop, anyway,” said Steve cheerfully. Then he sobered. “You’re the only one who can sort out your brain, and we’ve got a whole agency full of top scientists working on everything else. Really _brilliant_ people. Please, trust them?”

Except his earnest, open expression asked, _Trust me?_

_And if I say no, how will you stop me?_

_fuck fuck fuck fuck fuck_

“Fine,” he croaked.

 

* * *

 

Tony talked to Dr. Kafka. He talked to Samson. He stayed away from anything that would try to kill Thanos—there were too many errors in his brain, his math was off. Talking to psychiatrists turned into speculation about the most minute physical workings of the human brain, and he picked over their knowledge for his other personal project, which he could only think about in the most backwards way after tying his motivations into knots—so progress on that front was slow. And there was Bruce’s math, but that folded up under ‘things wrong with his brain’.

The sheer relief of it made guilt clog up his throat, all the more so because he couldn’t escape the feeling it was useless; there was no way he could speak freely to either psychiatrist. Loki knew... might know... but he couldn’t give Loki an inch, not one. Thanos might devour them all, destroy the cluster again as Loki had done once, but at least then he would only be unmade.

_Christ, you selfish bastard._

For the next two weeks Steve showed up to talk to him at least once a day and Tony let him talk, because he had no idea what to say in return—and because Steve brought with him materials, supplies, although of course he could have just requisitioned them from someone else in SWORD. Or have gotten them himself, despite the agent _still_ standing watch outside his door, he was always allowed to leave. But what was the point? His brain was throughout the entire complex, and in here was the extremis booster: the cabinet gained additions until it spread across the entire wall, more and more of it devoted to fixing errors that kept accumulating over time.

His model of the human brain wasn’t working. Something in his math was wrong—signals were not transcribing from point to point, _something_. It was the same problem with Bruce’s proof, all over again...

At some point, his brain began to drift. It might have been fatigue; it might have just been the slow accumulation of errors past what passive-debugging could fix. He sat, for a time, in a kind of stupor; numbers replayed themselves over and over past his awareness, but his higher programming was adrift. Eventually, the debugger took advantage of the available processing power and amped up, and he fell into a state not unlike sleep, except the only thing he dreamed of was numbers. Not exactly a nightmare. Not exactly _not_ a nightmare. They still all came out wrong. Within Bruce's proof reality and unreality merged, divided, and intertwined, until he couldn't tell them apart anymore, and point A was point Z was point theta. 

It was the graveyard shift, as much as SHIELD had such a thing, when something changed in his surroundings and he ‘woke’. Scans couldn’t pinpoint what it had been; it might have been internal, a random flux in brain chemistry. Knowing how to warp past the boundaries of the observable universe didn’t give him any insight into why the human brain needed sleep. Probably he should have spent more time on that while he’d had the library nexus at his fingertips. He definitely should have spent more time on extremis.

But he hadn’t.

He’d tried, he’d prioritized—maybe they were the right things, maybe they were the wrong things. _fuck_

It didn’t matter now. What mattered was that he’d run debugs and error-checks on Bruce’s math problem nine-point-two billion times and still not found the contradiction that he knew had to be there. There was a point at which repeating things that many times went past insanity, past stupidity, and into sheer blindness.

_i cant do this_

Part of him was still asleep; maybe that was why the thought didn’t seem as paralyzing. He was already paralyzed, his body frozen in sleep while his mind drifted among cameras, ghosting through SHIELD’s hallways. He let his attention linger in the hidden mics, picking up snippets of office watercooler talk—

“Did you see the specs for Banner’s room?”

“No, why? They up the Hulk-shielding? He gets coffee with the rest of us, I don’t know why he even—” 

“No, he’s building a gamma-irradiated _bunker_! Gonna be completely soaked in it, rads off the chart—it’s like he looked at a nuclear meltdown and decided it would make good office decor.” 

“Jesus, what, really?” 

_...huh that would definitely block spying..._

“It has to come from the aliens. Come on, how would anyone figure out not to say their names unless they were told about how they can hear them?” 

“Barton went to you-know-where after Stark’s funeral. Maybe he picked it up there.” 

“The new shielding tech could give them a run for their money. I bet the aliens have even better stuff. Whatever we’re seeing, you bet it’s just what they’re willing to share.” 

“If they were willing to share anything they could’ve helped with the zombies...” 

And, dreamily, though another camera and another set of mics:

“How’s it hanging, doc?” 

“Together, in lieu of separately, for the moment... thanks, Darcy. Mind setting it there? I’ve just got to finish aligning this...” 

“No prob.” 

Tony watched Lewis set the venti tea on a nearby rolling cart and continue on about her rounds, whatever those were. Bruce remained in the portal chamber, alone, using the gyro-arms to delicately assemble one of the focusing rings for the primary beam—a painstakingly slow operation; after each step everything had to be checked from the beginning, all over again, to be sure it all the components remained in alignment in three dimensions and in phase in five. When it was totally assembled it would be locked into a more secure container, but right now it was exposed, vulnerable. Bruce had already started over twice. The scientist who had put the last one together had thrown a screwdriver at the wall after her third attempt.

Extremis could do it, if he weren’t throwing so many errors.

Bruce was careful. Painstaking. Patient. Human.

Tony clicked the intercom on, sending part of himself into it, taking up space as something less than human. _“Bruce.”_

Bruce set the current component and turned it to check-mode, then looked up. He was directly in front of Tony—directly in front of a camera; at the moment they were one and the same. “Tony? I’m kind of in the middle of something, here.”

“ _Nine-two-three-eight-one-four-one-five-six-seven,”_ said Tony. The numbers came out by themselves; forming sentences seemed... hard. Too much memory devoted to debugging. He didn’t want to stop it. Not yet.

“Uh,” said Bruce. He took off his glasses and set them on the tray next to his tea. “Should I be calling Steve?”

“ _I can’t find it. That’s the definition of insanity, right? Maybe it’s the point where I’ve gone wrong. I need to find it...”_

“Tony.”

“ _Your math. Proofs. Proof by contradiction. So where’s the contradiction?”_

“I didn't use any proofs by contradiction in what I gave you.”

“ _But you contradicted.”_ Oh. That... hurt, a little bit. Maybe he should... the debugger flowed over him, quarantining, easing away the uncertainty. Higher thought was content to rest. Lower thought waited for command.

“Send it to me,” said Bruce, picking up his glasses and going over to his workstation. Tony flowed into the workstation and crystallized numbers on the screen. Run number nine-two-three-eight-one-four-one-five-six-eight. Bruce _hmm_ ed, his eyes tracing the images slowly, oh-so-slowly. Human speed.

“Tony?”

It had the indications of an enquiry, but there was no question to answer. Tony didn’t say anything.

“...go to sleep, okay?”

That was a command, and an enquiry. _“Okay,”_ Tony confirmed, and the world cut out.

 

* * *

 

“And you can’t just use earbuds?”

“Uh—no, sir. It’s a safety issue.”

Steve was beginning to wonder if everyone saved up the stupidest complaints to turn over to him. “Dr. Nguyen. Dr. Foster and Dr. Banner are your team-leaders.”

“Yes, but—”

“If you have a concern about your working environs, take it to them first. But I am not overruling them about whatever music they want to play in the Gateroom,” Steve said flatly. “Unless you’ve an issue that actually matters, I don’t want to see you in here again.”

“But—”

“ _Out._ ”

Steve rubbed his forehead as Nguyen finally left—a defeated slump to his shoulders that meant, hopefully, that the guy wouldn’t be running off to Hill. Or maybe he already had, and she’d punted him back to Steve, just like Steve had tossed him back to Bruce and Foster. On the other hand... that pair could take care of themselves.

“Getting caught up in the music war?” an amused voice floated over from the doorway; he looked up to see Natasha standing there. At his arched eyebrow, she sauntered in, taking the chair that Nguyen had vacated.

“What, it’s a war now?”

“Oh, yes. Bruce took tyrannical control after one of the techs nearly sent another to Medical over it—you should have seen it, it wasn’t funny.” The look on her face suggested that it had, in fact, been pretty funny. “I guess they’ve gotten over the scare if they’re trying to get around it now. Bruce’ll be pleased.”

“Thrilled,” Steve muttered, and leaned back in his chair. Natasha was wearing an outdoor coat and boots, casual civilian garb. “What’s up?”

She glanced down at herself. “This? Oh. Just a personal project that isn’t going so well, anyway.”

“Anything I can help with?”

Natasha looked down at the desk, tracing a pattern over it with her fingers. “Tony tossed away a lot of good people.”

Who...? “Pepper?”

Natasha’s mouth twitched downward, but her expression was too swiftly controlled for it to become a frown. “I’ve been looking for her. She’s better at hiding than I thought.”

“I’m sorry.”

“Not your fault.” Natasha grimaced again, a full expression this time, and shook her head enough to get her curls out of her face. “At least you won’t tell me I’m wasting my time.”

“Natasha...”

“Never mind. So when do the eggheads think the Gate’ll be ready to open, anyway?”

“It’s more like firing a gun,” Steve muttered, but accepted the change in topic. “Still on track, music and all. They’ll be ready to start using the viewer Monday... or to go through to a world we know about.” No reaction from Natasha. “Which you already know.”

“I may have gotten a memo from Hill with a big question mark and your proposal attached,” Natasha admitted—then, at Steve’s dubious look, “What passes for a big question mark from Hill, anyway. You have to know how to read between the lines, with her.”

“Right.”

“Really. Okay, fine, I’ll say it—you can practice your arguments on me, anyway.” She straightened up, her voice deepening comically. “Captain, we’re in a war against universal annihilation, and you want to go play Red Cross on Planet Skynet?”

Her intonation had shifted, matching Fury’s almost perfectly even with her still-feminine voice. Steve goggled at her.

“Very convincing, Captain,” Natasha added, voice mercifully her own once more.

“Tony could take down ULTRON,” Steve said after a moment.

“Really? Latest report out of psych says he only _just_ directly admitted he was throwing errors.”

“Psych reports are supposed to be confidential.”

“Is that why you're not reviewing them?” Natasha asked. Her voice was even and controlled, but he’d almost have preferred it if she’d snapped the words instead. How did she disengage like that? “Somebody needs to—and you did put me down as your second.” Her aloofness was almost like a dare— _say that you regret it now._

He did—briefly, an irrational flare of anger. But she was right. Tony was his responsibility, and since he couldn’t bring himself to read the reports out of psych... “Fine. Thank you.”

“You’re welcome.”

“My point still stands. Maybe extremis isn’t the answer, but Tony shut down ULTRON without the help of extremis.”

“I’ve read your report on that. It would shut off all of _our_ tech, too.”

“There’s a counter for that.”

“That would let ULTRON right back in.”

“Well, Tony could figure out a way around it—”

“ _If_ Tony’s up to figuring out anything other than his own head, you know as well as I do that there’s more urgent things he ought to be working on.”

Steve flattened his palm against the desk. “Damn it, Natasha—I promised them. I said we’d send aid. They _need_ aid.”

“And I’m not saying it’s not a laudable goal, but, Steve—this isn’t an op where you can go in carrying what you have on your back and save the day. This is logistics. It’s hard enough for us to send enough aid to individual countries. We’ve still got places reeling from extremis, the Christmas tsunami, China’s bombs, places hit by sectarian violence, protests, civil wars—and now we’re talking about an entire _world_. And that’s without even considering transport. I talked to Bruce—opening just one of those portals drains one of the new Makluan reactors. We won’t be able to transport much.”

“The difference we make might be small. I know. That’s better than no difference at all.”

“But while we’re using the Gateroom to send aid to that world, we’re not using it to make allies against Thanos. It’s never going to fly, Steve.”

He grimaced, setting his jaw. Natasha’s lips twitched downward in response.

“We can’t give up on them.”

“And we’re not.” She shrugged. “Isn’t that the point of SWORD? The real one, if you strip away the political scheming? Come together, share tech... maybe we’ll find someone on another world who has a better way. But right now, if we help one world, we’re not helping the rest.”

“You can’t turn lives into numbers.”

“Then find another way to work that out. You’re contracted as a division deputy commander now, not a strike force leader. You need to see the big picture, Steve, or you’re going to get a lot more people killed. Maybe everyone.”

 _Damn it._ “Fine. I’ll postpone that plan.” He sounded surly even to his own ears—surly, and hating it. “But I’m not giving up on it.”

“No one’s asking you to, Steve.”

It still felt like he was giving up on something.

After another meeting with Legal on their latest response to USMil—which was to continue with vague promises; nobody in their right might expected them to have anything yet anyway, because nobody in their right mind collected as many geniuses as SHIELD had under one roof—Steve went to see Tony. He’d been trying to make it a habit over the past few days. Tony’s ‘lab’ wasn’t much like his workshop had been, but there was still a hint of the familiar about the routine.

Although maybe coming right after a meeting with lawyers wasn’t the best idea, Steve had to admit to himself. He paused outside the door and forced himself let the frustration go. By the time he’d finished the rote breathing exercise that went along with doing so, the door had opened. Tony had even remembered to turn on the lights this time.

Steve stepped through and closed the door behind him. Tony had started adding server cabinets along one of the side walls overnight. At this rate, the entire room would soon be filled with extremis alone, no space for anyone within it... a disarmed but still dangerous disease, right at the heart of New York. He felt a flare of disgust at the thought and tamped down on it, hard. The extremis that the Makluans had was radically different than what Borjijin and Hansen had turned it into.

“Tony?” he asked, carefully, after a moment. The room was apparently empty. The door had opened for him, but that didn’t mean—

The thought was cut off as Tony stepped _out_ of one of the cabinets, extremis trailing off of him like liquid mercury. But mercury would have dripped downward, not sideways, back into the cabinet that it had come from. Tony shook his head, shedding silver droplets that fell to the floor and promptly rolled back to the cabinet. A coil of extremis followed him, connecting from the bottom of the cabinet to one shoe, merging into his clothes.

“When I was in high school the science teacher broke a mercury thermometer once,” Steve remarked. He smiled as the memory came back to him now—mad old Mr. Grant. Although, if he did the mercury thing with all his students, no wonder he’d been strange. “Let us chase the little drops around or stick ‘em on paper to feel how heavy it was. There wasn’t enough to try floating anything in it, though.”

“Jesus. Health and safety of the forties.”

“Thirties,” Steve corrected. “Although mostly we thought he was crazy for breaking a thermometer. They weren’t that cheap.”

“Uh-huh.” Tony slouched over to his desk, taking a seat—Steve was pretty sure that Tony didn’t actually use the chair except when there were other people around. Of course, if he was just _merging_ with his extremis servers...

“You can breathe fine in there?”

“No, Steve, I’m deliberately giving myself brain damage,” Tony snapped, turning away sharply—not quite flinching at the end of his words.

 _Don’t reply._ Steve held his thoughts in, letting the hurt and then the related irritation pass. He studied Tony’s hunched form. The inflection had been just a bit too _deliberate_ , the sarcasm lacking a barb. Was that a test? _Let it go_.

“Well, it does look an _awful_ lot like mercury,” Steve said at last, lightly, when he could.

“Ha. It really doesn’t.”

Steve let that one go, too. He leaned against the wall and shoved his hands in his pockets instead— _don’t cross your arms_ , the memory of Natasha’s voice warned him, _don’t put your hands on your hips—it’s confrontational and you’re a big guy, Steve._ That had been months ago, in a completely unrelated situation, but it probably still applied. “So... what’re you up to?”

The sharp way that Tony looked up told him that he’d missed casual, unless Tony was just being... Tony. _Damn it._ “What, checking up on me? Security cameras not enough?”

“No,” said Steve evenly, “I just figured it had to be more interesting than meetings with Legal, which is all I’ve done today.”

“Small talk? Really?”

“Sure, if you consider whatever you’re working on _small_ ,” Steve goaded.

At last, that earned him a smile—a sickly, unenthusiastic one, but Steve would take what he could get. Around them, something changed—Steve tensed, moving away from the wall and into a balanced stance as the air hummed. It sounded almost like the AEDs, but not quite...

“Relax,” said Tony. He hadn’t moved, his eyes sharp and watchful. “That was me. Upping security.”

“You’re in the most secured building in the world, Tony.”

“I’m _in_ it, it can’t be that secure,” said Tony, and before Steve could work out exactly what he was trying to say with that, he continued, “I was going to tell you this, anyway, I figure now’s as good a time as any. Something I needed to figure out, anyway, after Tem and Maya—I mean, given what they—”

He was rambling, unfocused. Steve held up a hand to cut him off before the beginnings of anxiety could become something more. “Have you found something about them?”

“No.” Tony flashed a brief, tight-lipped smile, there and gone. “I’d tell you, if I had, but—no.”

“I trust you, Tony.”

“You do, don’t you?” Tony asked, looking at him a little oddly, a little fondly. Steve raised an eyebrow, resisting the urge to squirm beneath the scrutiny. A moment later, Tony flicked his eyes away again. “Well, if you’re going to insist on it—I made you an override.”

Steve had to pause a moment before he could keep the sharpness from his voice. “For what?”

“For me.”

“Jesus, Tony—”

“Override 54. Say that in range of any pickup I’m on, and extremis shuts off. Try it.”

“Tony—”

“There’s no override I can build that I can’t workaround eventually, but this one’s sufficiently complicated that it’ll take me a while, and I wrote it so that my brain, um, won’t see it coming. You’ll have to move fast, but it’ll give you—”

“ _Tony._ I’m not going to use the mantra on you.”

Tony was studying the floor. “Well, it’s a third option.”

“I trust you.”

“It’s not actually about that. You’re—you might not be—the only one who... knows.”

_Loki._

“There has to be a way to get it off you.”

“There isn’t.”

“Some way. Indirect. We’re back home now, Tripitaka’s gone, we’ve got all the resources of SHIELD.”

Tony’s head snapped up, eyes wide. “You can’t tell them!”

“I won’t!” Steve held up his hands, placating. “That’s not what I meant. I meant you’ve got a lab, you’ve got more tools—” He cut himself off. Tony’s face was growing more pinched with every word, and abruptly, Steve realized that it wasn’t anxiety. It was pain.

“I can’t,” said Tony after a few seconds, quieter. He winced, rubbing at his temples with both hands. “I can’t. You think I wouldn’t like to? I can’t even consider _considering_ it without a goddamn migraine.”

God damn it. “I’m sorry,” said Steve.

“Not your fault,” said Tony. The pain in his expression eased away and became tiredness. “I need you to have an override, Steve. Please. For my own peace of mind.”

Slowly, Steve nodded. “If anyone else tries... okay. I’ll use the override, if I have to. But I don’t need to test it on you to believe you when you say it works.”

“Because you trust me.” There was a thin edge of sarcasm about the words, barely there. “You shouldn’t.”

“Well, you’re a bad judge of character, so excuse me if I ignore that,” said Steve. He pulled out his phone, flipping it into holographic mode to increase the screen size; on a flat surface it could project a keyboard, turning it almost into a proper laptop. He gestured at the desk. “Do you mind if I get some paperwork done? Legal’ll have my head if I don’t.”

“Captain America, scared of the briefcase brigade.” But Tony rolled his chair back close to the cabinets behind him, leaving the desk free. Steve didn’t miss the way that the rope of extremis thickened as he did. One lazy gesture indicated the chair opposite the desk. “Be my guest.”

Months ago he wouldn’t have had to ask—they’d gotten past that point. Steve would have just wandered in and claimed a spot on the couch, or at one of the tables that Tony wasn’t using. Asking felt like backwards progress; the slight bitterness in Tony’s voice, more so. But he’d never get anywhere not trying.

Legal’s endless documents were too much to face. He pulled up the latest reports on the hunt for Borjijin and Hansen instead, and grimaced. Sometimes, trying didn’t get you anywhere, either.

 

* * *

 

Monday morning’s test-run of the portal didn’t go so well. By Monday evening Foster’s team had finished repairing the damage, though, so Steve crowded back into the Gateroom, behind the thick observation wall, and watched as they ran through the pre-demo checks again.

“ _It’ll work this time,”_ Tony’s voice said in Steve’s ear. _“First calibration’s always wonky. Mine exploded, too.”_

“Oh, great,” said Steve, carefully suppressing the hope that had risen in his chest. Tony’s voice in his ear, unprompted... Tony hadn’t _started_ a conversation with him since before they’d returned from Maklu. “Some warning might have been nice.” None of the scientists crowded around him paid any attention to him talking to himself, too used to earpiece-wearing superiors. But Steve kept his words carefully generic, nonetheless. The rumours around this place regarding Tony were outlandish enough that even Steve heard them from time to time—admittedly, mostly from either Natasha or Clint.

“ _Nah, they know what they’re doing, it was expected.”_

It hadn’t seemed _expected_ this morning... although, granted, Steve and the rest of the scientists were standing behind six feet of transparent steel. “Still could’ve saved time.”

“ _It’s a calibration thing, Steve,”_ said Tony, echoing Steve’s own annoyance back at him. _“I knew it_ probably _wouldn’t work. So did Bruce. But until it’s tried at least once there’s no way to know which way to adjust it. Now they do, and have.”_

“Right. Sorry.”

Silence in his ear, and Steve regretted—“Captain,” said one of the techs, before he could say anything further to Tony. _That went well._ “We’re ready to go.”

He glanced across the room to where Bruce and Foster were standing with their heads bowed together over one of the screens. “Whenever you’re ready, doctors,” Steve called to them.

“Alright,” said Foster, her voice not quite as nervous and excited as it had been this morning. Her hands were hovering over the keyboard. “Test run number two starting... now.”

The observation wall blocked most sound, but Steve could still _feel_ the whine on some level as the lasers began to cycle up. Unlike in Tony’s Ohio mine, the lasers here were mounted on a floor rig rather than hanging from the ceiling, and since the observation room was elevated several feet above the Gateroom’s floor, that meant he could watch the glow build up in front of the apparatus before the lasers engaged. The filters in the wall turned everything an unnerving, corpse-light green, which Steve tried not to take as an omen. There were no explosions this time as the portal engaged, blooming out from the laser array like a bubbling pool tipped ninety degrees to the horizontal. When it stabilized enough to be looked through, the scene shown was odd: it was like somebody was taking video of a skyscraper at a weird angle. The idea had been to aim the window at cities, but this barely showed anything.

At least, not visually. “We’re getting data!” exclaimed one of the techs. “Sensors are calibrating—”

“Oh, that’s not good,” murmured Bruce; Steve crossed the room to stand behind him and Foster.

“What’s not—oh,” said Foster, her eyes going round. “I see. Okay, uh, we’re okay, only a safe amount’s actually getting through.”

“What’s wrong with it?” Steve murmured, very quietly, so that neither Bruce nor Foster would hear. But Tony would—always had.

“ _Rad count’s way too high,”_ said Tony after a moment. His voice was duller—darkened by his own memories of ULTRON’s world, maybe. Steve stiffened. _“Step through... even you’d be dead in minutes.”_

Like the world that Anthony had accidentally dragged him to, which would have killed him without the intervention of an other-worldly group of benevolent scientists. Damn. “Is there anything to be gained from monitoring this world, or should we move on to the next on the list?” Steve asked, loud enough for both Bruce and Foster to hear him.

They both jumped, startled out of their observations. “This is a portal to _another world_ —Captain, this is the most amazing—”

“I know, Dr. Foster, but we can set up another just as easily.”

“Well—yes, but—” Frustration covered her face. Steve didn’t know her well, but it wasn’t hard to guess at the source. Foster was SHIELD’s premier scientist on extradimensional travel, and had been trying to open a portal like this for over a year—this was the moment of a life-time, a mighty step for human-kind.

But to Steve it wasn’t exactly new. The extraordinary had long ago become common-place; portals to other worlds weren’t sources of wonder anymore. Briefly, he regretted the loss—and then firmed his voice. “But nothing, Doctor. Unless there’s more calibration you need to do, we should move on. I’m sure you can learn more from a place you could actually _visit_ , right?”

“Not necessarily,” she muttered, but Bruce shrugged and said, “Calibration wouldn’t hurt, Steve.”

“Alright. Keep it open until you’ve got it down. But then we need to move on.” They were, after all, decades—centuries, millennia—behind the powers out there.

They needed to find allies.

Over the next week, three rotating Gateroom teams opened windows to one hundred forty-seven different worlds. Fifty-two, including the first, contained background radiation levels strong enough to prohibit further exploration. Nine showed no radiation, and the ruins of cities, but no apparent human population. Twenty-nine showed no signs of human civilization past or present. Sixteen were fighting world wars. Seven showed aliens in control of the Earth instead, leading to arguments about whether they were invaders or just the product of a different evolutionary path. Eighteen showed human civilizations too technologically primitive to be of any help—and no signs of magical advancement, either. Eleven showed only black space, no Earth at all.

Eight were put on the list for further assessment as possible allies, including three of the alien worlds.

Bruce stopped attending after the first three days, which was when, satisfied that the lasers wouldn’t melt themselves down, the third Gateroom team was added and they went to twenty-four hour exploration. Foster, on the other hand, wasn’t content to hole herself up in her lab to play with the data they were gathering; she brought her notes to the Gateroom and worked on them there, scattering notebooks and laptops everywhere in her wake and catching about two hours of sleep a night. Steve continued to attend whenever he could. The sight of black space where Earth should have been was the most disturbing, particularly the one case where the techs had determined that the _sun_ was probably there... but there was nothing orbiting it, no other planets at all that they could find. Steve had told them to move on.

Had that Earth been destroyed? Or had it never existed at all? When he asked Foster, she snapped that it was impossible to know the answers when he wouldn’t let them spend more time taking readings on unsuitable worlds.

“Hard to say,” said Tony, when Steve posed the question to him a few days later.

It was a windy day, but March had finally decided to be more docile than February: the wind didn’t cut into the skin like it had been. Steve’s morning had been... not wasted, but spent indoors, debating with the Council regarding funding and building a second Gateroom. That, at last, had been approved—they couldn’t keep hunting down new prospects and also observe the worlds they’d tagged without a second portal device. Steve had neglected to mention that one had unofficially been in progress almost as long as the first.

“The astrophysicists found it exciting, either way,” said Steve now, shaking his head and shoving his hands in his pockets. He’d forgotten again to bring gloves.

“They would,” said Tony, still hunched over his coffee. Or so he looked to Steve, anyway—but then, with the ICG up, Tony also looked nothing like himself, features altered enough to be total stranger. He was blond again, although this time it was seamless instead of a bad dye job.

The coffee, prepared by an obscure bistro that Natasha had recommended, had been the bribe Steve had offered to lure Tony out of his lab and on this field trip out to Central Park. Of course, Steve was pretty sure that if he’d just _asked_ , Tony would have agreed. But offering the coffee as a bribe, not-quite-explicitly... it had amused Tony, at least. And hopefully it had driven in the idea that Steve really was _asking_.

 _Just keep trying,_ Steve told himself. At least Tony seemed to be enjoying his coffee.

They strolled onward through the park, avoiding others taking advantage of the turn in the weather—the AED in Steve’s pocket might prevent electronic eavesdropping, but it wouldn’t stop anyone from simply overhearing them. And Steve would have to switch it off whenever they passed too near someone with a cell phone, unless he wanted to make them lose their call.

“So many of them are just... wastelands,” said Steve, after a bit.

“What did you expect?” Tony’s voice was carefully neutral—too carefully. Steve looked over, but he was still staring down at his coffee like it held the answers to the universe. “Casualties of war.”

“Maklu was trying to protect us.”

“Maybe they should have cared more about themselves.”

 _Don’t say it, don’t say it_ —Steve clamped his mouth shut. Any accusation he might have thrown back in reply was false—if there was one thing that Tony hadn’t done, until _ordered_ , it was care about himself. Steve made himself take a breath, thinking carefully over his reply. “I’m glad you are. Finally.”

 _That_ got him a look, an upwards glance from narrowed eyes. “What, checking up on me? Don’t worry, _mon Capitan,_ I’m being good and selfish.”

“Good,” said Steve, matching the bitterness in Tony’s tone with sincerity. “I’m glad.”

Tony deflated, prickled pride rushing away from him. “Yeah. Well. Who knows how much help I’d be anyway.”

“Have you been...” Steve fumbled for words that weren’t ‘getting better’. “Making progress?”

“Human brains are weird. Extremis is easy by comparison.” Tony took a sip of his coffee, then picked up the pace a bit—but he’d perked up, Steve noted hopefully; that was a good sign. It wasn’t running away, it was energy. Anything other than the slump that Tony seemed to have been wearing for weeks. “I’m getting a better model on extremis’ interaction with outside protocols—Bruce had some weird math, gave me a few ideas in other directions, and to extremis the human brain _is_ an outside protocol. It can mimic the structure of neurons to replicate functions, but the actual information feed is different and how it processes that is phenomenally elegant, much more flexible than it needs to be, there’s way more it could be doing. Working it out seems to be helping the debugger. I’m getting less errors.” He shrugged, deprecatingly. “Still some. Too many.”

And there was that slump again. “Progress, Tony.”

“Not enough. Not fast enough.” When Steve didn’t reply, he added after a moment, “Feels like we’re just... waiting.”

 _That’s war_ , Steve thought, but he kept his mouth shut.

The fresh air did them both some good, though, and by the time they met the SHIELD driver back at the nondescript sedan, Tony had relaxed enough that he was trading lawyer jokes with Steve. Then, halfway back to the NYHQ, stuck in the middle of traffic, Tony froze up. His eyes began glazing over the way they did while he was working in his lab, and Steve leaned forward and tapped his knee. “Tony?”

“Pepper’s there,” said Tony, sounding very far away. “She—why is she there?”

“Natasha’s been looking for her,” said Steve, trying to pitch his voice low and calm. Somehow it was harder than trying to do the same thing for a panicking civilian. He’d thought Tony was making progress—he hadn’t expected _Pepper_ to set him off, of all people.

“But she’s supposed to be out,” said Tony, His breathing was shallow, and becoming more rapid. “She—I—after everything, I—” Steve could see the uptick in his pulse at his neck; Tony had clenched his hands into fists, knuckles turning white. “There were funds. She deserved better, but at least I could—”

Steve pulled out his cell phone and hit the speed dial for Natasha. “Natasha.”

“ _He has a tracking program on her, doesn’t he?”_ Natasha answered, sounding resigned. _“You can reassure him—or I guess I can, hi, Tony—I plan to stick to her like glue while she’s here. She’ll be safe.”_

“That’s... not actually the problem,” said Steve, looking at Tony, who was now hunched over, halfway curled into a ball that emanated shame and misery—and panic, too, if the slight but constant shaking was any sign, or the rapid breathing. “Can you get her housing elsewhere, Manhattan? Tony mentioned funds.”

“ _He doesn’t want to see her?”_

“Now’s not the best time.”

“ _She’d like to see him,”_ Natasha said gently. _“Sometime.”_

“I don’t think—”

“No,” said Tony, and Steve heard it over the phone, too, _“No. I’ll see her. I owe her.”_ He stopped speaking aloud halfway through; his electronic voice was far more stable.

“ _It doesn’t have to be today, Tony.”_

“ _But it should. I owe her.”_

Tony’s face was tight and unhappy, but determined. The panic looked like it was starting to ease up—he was holding it together, breathing evened out into the unnatural, fixed rate of someone consciously controlling their breaths. If he thought he could do it, work through it... “It doesn’t have to be at SHIELD, either.”

“ _No. My lab.”_

“Do you need the shielding?” Steve asked carefully.

“For chrissake, that happened once, when I was being _attacked,”_ Tony snapped, out loud—no longer tripping over his own words, and Steve relaxed a bit further. “The power will be fine, I haven’t done a goddamn thing to the power since. My lab. I want—let’s just, do this privately.”

“ _Alright,”_ said Natasha. _“We’ll be waiting.”_

The remainder of the drive back to the NYHQ felt interminably long. Steve tried to make conversation, but Tony barely replied, instead staring off into space with the thousand-yard stare that he wore so often now. If Steve hadn’t known he was using extremis, he’d have long ago dragged him to medical on the basis of that stare alone; it was creepy, watching him like that, let alone when he did it for hours and hours. He was probably using it now to keep an eye on Pepper and Natasha at the NYHQ—spying on them, which was something else they needed to talk about. Steve stifled a sigh.

Tony vanished when Steve went to get out of the car, there one moment and invisible the next. The back of Steve's neck prickled with foreboding. He held the car door open for a few seconds longer, trying to listen for the sounds of Tony’s boots—regular or jet-boots—on the concrete floor of the garage, and after a moment heard his almost sub-audible footsteps. Someone with normal hearing wouldn’t have been able to, not over the sound of the car engine. Steve shook his head and pushed the door closed before the driver could get concerned. “There’s no one here to see you.”

“ _There is in the hallway.”_ Frowning at that, Steve made for the door that would take them into the NYHQ’s main complex. He had to hold that one open a second longer than normal, too, which got a look from the agent on guard duty, but evidently Captain America was trusted enough that he wasn’t questioned.

Which was a security breach. SHIELD had face-altering technology, even if it wasn’t up to Tony’s standard of illusions. He made a mental note to bring it up with Hill.

The hallway at the other end of the elevator ride had more people in it—more than normal, half a menagerie of agents standing around awkwardly, like they were embarrassed to be on guard duty over the visitors here. Steve raised his eyebrows at them, which made them shuffle aside and get out of his way long enough for him to get to the door without worrying that one of them would move and run into Tony.

The door opened on its own, proof that Tony was still watching even if he had possibly run away, and Steve stepped through to see Natasha staring at Tony’s extremis cabinet, which had now grown so large that it covered half the room. Clint was picking through printed pages of math on Tony’s desk with an expression that looked close to bemusement. In front of the desk was Pepper, sitting primly in the chair that Steve had dragged in for his own use. Her clothes were practical—jeans, sneakers, a sweater—and, while clean, clearly worn. A far cry from a CEO’s power suits.

The door slid shut behind Steve, again without any prompting from him. Pepper opened her mouth to speak and then cut off, abruptly, as Tony blinked back into view beside Steve. Natasha and Clint both went still.

“Hi,” said Tony, low and awkward. His hands were stuffed into his jacket pockets. Here, in the warmth of the lab, he looked ridiculously overdressed, layers upon layers of extremis-formed clothing. 

Pepper closed her mouth on whatever she’d been about to say, then opened it again, and asked, “Teleportation, huh?”

“Invisibility. Actually.”

“I imagine that could be... useful, living with SHIELD.” There was a none-too-subtle emphasis on the last three words.

“Still not the worst thing you’ve caught me doing.”

“There was a lot I never caught you at.”

Steve caught Tony’s flinch, a barely ripple in his shoulders, but Tony didn’t drop his gaze. “I’m sorry.”

Pepper stared at him. “Well. That’s a start.”

“That’s an end.”

“Tony,” said Steve, taken aback at the rudeness. Tony didn’t look in his direction; neither did Pepper. The tension between them was so thick it could have been cut by a knife, and Steve felt like an intruder just for being in the same room. Natasha and Clint were like two statues. This felt uncomfortably like walking in on a lovers’ argument, except worse, because the entire thing was worse. Tony and Pepper had known each other half their lives. Tony looked calm, but eerily so—it wasn’t real.

“Natasha,” Pepper said calmly. “Clint. Steve—good to see you again. Could you give us a moment, please?”

“Yes,” said Natasha, already moving swiftly for the door, but, “No,” said Tony, before she’d taken more than a step, before Steve could do more than reach for the door handle. “No.”

“No?” Pepper’s looked as cool as a cucumber; she didn’t need the power suit to pull off _power_. The swivel-chair she sat in could have been a throne.

But Tony, Steve was reminded in the next moment, had played the role just as long as she had, had been born and bred to it; he didn’t back down, squaring his shoulders and saying, “No. I’m sorry. But that’s all I have.”

Pepper stood, slowly and deliberately, the placement of her feet like ballet. “Nineteen years. You owe me more than that as en ending. You _owed_ me more than that.”

 _We should leave,_ thought Steve, desperately. His gaze flicked over to Natasha, who shook her head, minutely. She didn’t think that they should be left alone? Something must have showed on her face, because equally minutely, she tilted her head toward Tony.

If Tony noticed the byplay, he gave no sign of it; the whole of his focus seemed fixed on Pepper. “You never wanted to do this.”

“That was years ago. I changed my mind early on.”

“Still too late.”

“You owe me,” she said, every word very deliberate, “more than cruelty.”

Something in Tony’s expression cracked. “It’s not—Pepper, it’s not—”

Pepper walked toward him, and Tony flinched. Steve took a step forward, not quite placing himself between them. “Pepper...”

As if suddenly remembering that there was someone else in the room, Pepper broke her gaze away from Tony long enough to look at Steve—and then back to Tony, again, frustration written all over her. Frustration, grief... all the familiar things that Steve could sympathize with, compounded by the cruelty that Tony was displaying—except maybe it wasn’t by choice, because Tony’s voice was hoarse as he said, “Don’t. Please. Pepper.”

“This is all I have left,” said Pepper. “I’m not starting over, Tony. I don’t _want_ to start over.” She stepped forward, Tony stepped back, and Steve caught his shoulder as he interposed himself more fully between them.

Instead of thick synthetic fabric beneath his fingertips, there was the smooth metal of plate armour. Steve’s head swivelled around, his attention broken from apologizing to Pepper, to stare at Tony instead—Tony, who looked white-lipped and wasn’t saying anything, and who had to be an illusion.

“Pepper,” Steve said carefully, “this isn’t a good time.”

Pepper drew in a breath, but her voice had returned to that carefully calm measure. “Will it ever be?”

“I don’t know,” said Steve, his eyes flickering over the illusion. It was flawless—he could see the pulse at Tony's throat, hear the faint exhalation of his breath. “Not now.”

Natasha and Clint stepped forward, then, and Pepper looked between them in frustration—them, and Steve, and back to Tony, who still wasn’t saying anything, wasn’t moving one illusory muscle. For a moment betrayal played over Pepper’s face, before it vanished beneath a mask of calm, and Steve felt his stomach twist. This wasn’t her fault, and she didn’t deserve this. “Sorry,” Steve tried, but it was far too little, and he deserved the look that she gave him as she left. He’d need to apologize properly—later, when he could maybe explain things better.

The door didn’t open for her automatically. She had to pull it open, and when she and Natasha and Clint were gone, Steve had to pull it shut again, too. He made sure it was locked, flicked on his AED, and turned back to Tony—who by now was putting a better impression of a statue than Clint and Natasha had, earlier, because statues didn’t breathe or make any of the other almost imperceptible motions that characterized living humans, even at their stillest. Tony had stopped animating the illusion.

“Are you okay?” Steve asked, stepping closer.

It took Tony a long time to reply, long enough that Steve wasn’t certain if he should say something more. He’d spoken to Leo a few times about anxiety attacks, but theory was a long way away from practice. But eventually Tony said—the image of his mouth not moving, and not in his voice, but in the armour’s— _“I need. A minute.”_ It was inflectionless and stilted, more robotic than Steve had ever heard him before.

“Okay,” said Steve. It took effort, but he managed to tear his eyes away from Tony’s unnatural image, and went over to sit in his chair—a moment later realizing that maybe that wasn’t the best idea; Pepper had been sitting in it just before. He suppressed a wince and didn’t bother to get up, propping his elbows on his knees in the least Pepper-like posture he could think of instead. After a few minutes, he pulled out his phone—there was no connection with the AED on, but he had downloaded files to review. Or at least to look like he was reviewing. He didn't manage to actually tear any of his attention away from Tony.

Metal shifted against metal, then clattered against concrete, and Steve sprang up from his chair. Tony’s image was still frozen, but that _sounded_ like Tony had just fallen over, or fallen to his knees—“Come on,” said Steve, “It’s just me, you can turn the cloak off.” With it on he was left hovering uselessly, or else fumbling around trying to figure out where Tony really was.

It flickered out after a moment—an actual flicker, not the smooth immediacy Steve had become accustomed to—and Steve crouched. Tony was still in the armour, but on his knees and hunched over. The armour was even shinier than normal, and malleable beneath Steve's touch; Tony wasn’t holding the nanites fully together. It felt like Steve’s hands were sinking _into_ Tony’s arm, and he had to suppress a wince.

“It’s fine,” said Steve. “It’s just me, I’m the only person here. You’re going to be fine...”

He hoped. But he’d thought Tony was doing _better_ before this.

 

* * *

 

Using the Time and Space Gems provided a clear-cut certainty that was more addictive than coffee or alcohol. The Gems flattened everything out so that points overlaid each other, infinity in the infinitesimal, and it was both a staggering wrongness and so near to perfect understanding that he couldn’t help but cling to it. But he couldn’t take it with him. He didn’t have enough processing power, enough memory, to hold the universe in his head.

The world reformed about him, space and time becoming concrete rather than abstract representations of frequency space, and uncertainty rose again like bile in the back of his throat. His hand—he had a physical hand again, now, where a moment ago he hadn’t—he had a moment ago, now, too—clenched tightly around the Gems.

Here he was, ready to ruin yet one more life.

“She’ll live. Cut your losses.”

_Christ, when I think I can’t sink any lower._

Clint was the one who’d set up this safehouse for Pepper, vetted the guards, arranged for contracts so that she could hire them herself with the emergency funds Tony had squirreled away in one of his fits of paranoia. The security systems were topnotch, completely isolated from outside interference, unless you had a head full of alien technology that made the best Earth had to offer look like banging two sticks together. Tony slipped inside the system and set up to overlay it. The AEDs buzzing at the edge of his awareness were annoying: when they were inside the security system’s perimeter, he reached out and shut them off blind. Conversation reached the edge of his ‘hearing’:

“ _It’s not that I don’t appreciate everything you’ve done, but if you won’t help me—”_

“ _SHIELD can help you, and we can use your help.”_

“ _But not with him.”_

“ _He’s in a bad place. Once—”_

The Time Gem dissolved in his hand as he willed it around him. Eternity stretched out, incomprehensible, and _then—_ it flipped, into that pure and certain knowledge, in a place without Time or Space or anything except patterns, points of repeating actions, nigh-infinite waves that added up to create _Reality_ and which through the Gems could be almost, _almost_ seen—

Reality flipped back into existence. Pepper was standing alone in the small living room. The windows were open, but shaded to be opaque from the outside, and there was enough additives in the glass to confuse infrared as well. One of the guards was right outside the door, wearing a life-signs monitor; another, a mile away, monitored the external cameras in real-time, but not the internal ones. A compromise between privacy and security, and one that was going to go out-of-style once Foster figured out how to reconfigure the portals for intraplanetary teleportation... but only for a short time, if he succeeded, and was right about certain of the side-effects of that.

For this he formed extremis into actual clothes—casual clothes, clothes that they might have worn on one of their date nights in the Tower, if that had ever come to pass. The rest he shunted into subspace, letting the Silencer take care of whatever whisper of sound might have escaped from that action. He leaned in the doorway, watching her— _and that’s shortly going to become creepy, right._

The ICG faded without a whisper; the Silencer he expanded to ensure that the guard outside wouldn’t hear anything. Tony knocked on the doorframe and watched her turn—casual, half-absorbed in her phone. When she saw it was him standing there, and not one of her security people, she didn’t quite jump. Her eyes barely widened.

“Tony.”

“Pep.” He couldn’t help it; her name came out softer than he’d intended.

“I thought you were supposed to be on lockdown at SHIELD.”

“Yeah, well, what SHIELD doesn’t know...” could fill an ocean—a planet—a galaxy.

 _That_ earned him a raised eyebrow. “Tony.”

“Pep,” he parroted back at her, forcing the beginnings of a grin. “I need your help.”

“You changed your mind. That was quick.” _Too late?_ her eyes, just slightly too wide, mocked him.

“That was an act,” he corrected her. Lied to her, as easily as breathing.

Her eyes narrowed, now. “I supported you, Tony. I _would have_ supported you. But I’m through with being cut out of the loop on half of what you do. I want in. No more secrets.”

Tony shook his head. The words fell out, almost running on top of each other, too quick. “There has to be secrets. The guy we’re fighting can read minds. That’s why I need _your_ help.”

He could read the dismay on her face—because he’d known her for years, and she knew him just as well. That was why it had to be her—well, it probably could have been Natasha, but would Natasha go along with this? And Natasha was too close in, anyway, and he’d never trusted her as closely. No, there wasn’t anyone else like Pepper, not really.

“Tell me,” she ordered him.

“A plan won’t work if he can pick it out of my head,” he said, sticking his hands in his pockets. “Or out of anyone else’s head. But, you know, computer memory... it’s more malleable than the human version. So I’m dicing the plan up and hiding bits of it for later. I need you to be the lynch-pin—to give me the last bit of information so that everything else will make sense, at the right moment.”

“The right moment. And that will be?”

She was calm—poised. Her shoulders showed no sign of tension. It wasn’t yet too late to back out—he could change his mind, prevent her from throwing herself as a sacrificial sheep to the wolves— _not even the real threat but they’ll take her down christ how can I ask her to do this_

The answer was simple: because she _knew_ him. She’d know exactly how to get his attention, when even he didn’t know. And once upon a time she’d told him she wouldn’t watch him kill himself, but that had been years ago and they’d both changed, counted the cost of the bombs they’d built and hand-delivered. She was the former CEO of the most infamous ex-Fortune 500 company on Earth. She’d get the job done.

“Tony,” she said, focused, direct. “Tell me.”

He took a deep breath, and damned himself all over again.

 

* * *

 

“We have a problem.”

Most SHIELD personnel would have frozen upon hearing those words from Bruce while he appeared even-tempered, let alone as sleep-deprived as he currently looked. Steve noted that he’d waited until there was nobody else in earshot. There were still a few other people in the cafeteria at this hour, but they had the table to themselves. “Lay it out.” He didn’t bother asking when the last time Bruce had slept was—unlike some of the other top scientists of SWORD, Bruce could actually be trusted to know his limits.

“Have you seen this?” Bruce asked, slapping down a stapled stack of paper, one that had obviously been flipped through many, many times. The first page had a photocopy of a post-it note, with Bruce’s own handwriting on it: _Whoever figures this out gets to pick the music in Gateroom B for the next month.—Dr. Banner_.

Steve frowned. He hadn't realized the music war had migrated over from Gateroom A. “Somebody stirring up trouble?”

“What?” Bruce glanced down at it. “No, not that.” He flipped the first page over to the back. “This.”

‘This’ was a lot of math. Or at least, Steve was pretty sure it was math. It could also have been an attempt at translating alien coordinates, or computer code, he supposed. “And what’s that?”

“This is a pair of proofs about Euclid’s First Postulate. One proves it, the other disproves it,” said Bruce.

Whatever that was. “So one of them’s wrong?”

“That, or something in the basis for the both of them is wrong,” Bruce agreed. “But I put this up in the Gateroom two weeks ago. Since then half the NYHQ has been working on it. Probably half of _them_ have been crowdsourcing colleges, universities, whatever contacts they have—nobody’s gotten anything. Half a dozen attempts that looked like it, but didn’t work out.” He looked vaguely guilty. “It, uh, it’s turned into a bit of a... meme.”

“A... meme,” said Steve slowly. He knew what a meme was. He _thought_ he’d known what a meme was, at least.

“Yeah, it’s starting to become the, um, the new ‘it’ problem in mathematics,” said Bruce, looking guiltier by the second. “Google made an announcement this morning, they’re offering a hundred thousand dollar prize for the solution.”

Steve blinked. “Why does Google want—what is Euclid’s First Postulate?”

“That there’s one unique straight line between two unique points in... Euclidean space, these proofs actually, uh, they deal with a generalization. That’s not important. I don’t think Google cares except that it’s, well, it’s like the Millennium Problems, except this should be _simple_.” Bruce looked frustrated. “Both proofs are already _there—_ all that has to be done is to take them apart.” He eyed the papers with distaste, and took a long swig from the extra-large tea he’d brought with him.

Steve eyed the stack of paper again. It had been stapled with a power-stapler; it was at least fifty pages thick. ‘Simple.’ “You’re telling me about this because of the security breach? I assume there’s some reason that this math problem shouldn’t have been shared.”

“No, no, it’s too basic to be a security problem—it’s elementary mathematics, it’s not—it was a tangent I went on, then Tony went further down it—I think, it might be giving Tony problems, a logic error, or something—”

“So it has something to do with _extremis_.”

“ _No_ ,” said Bruce, a little bit too emphatically. Table to themselves or not, it carried. The rest of the cafeteria went still, staring, half-asleep agents and scientists suddenly turned into wide-eyed spectators.

“Doc?” said Steve, more pointedly than carefully. Bruce’s eyes hadn’t flared green. Steve’d spent enough time getting his butt saved by the Hulk to know all the signs by now, and they weren’t showing.

Bruce rubbed at his face. “I need more sleep for this.”

“C’mon,” said Steve. He picked up the papers, and his own coffee, and steered Bruce out of the commissary.

“It’s nothing to do with extremis,” Bruce insisted again, when they were past the double doors and into a more restricted hallway. Steve didn’t have a destination in mind, other than some place with less people. He thought he should probably be telling Bruce to go to bed, but obviously Bruce needed to get this off his chest first. Whatever ‘this’ actually was, and if he ever got around to explaining why it was important... “It’s the portals, though—the coordinates—the theory behind the methods we’ve... been provided, to determine coordinates, to use them with the portals, it’s not all there. This could be a bit part of it, but practically, it’s not important for that.”

“If it could cause problems with opening portals, that sounds important.”

“No, we have all the methods. Tony’s leapfrogged us over where this would come in.”

“You’re not acting like it’s _not_ important.”

“I’m not—it’s not, for the portals. I think.” Bruce hesitated. “Though it might mean something for the minimum transfer distance, but that’s not important right now. I think—I’ve been over this... twenty times, thirty. I think Tony’s been over it about ten billion times, but he might have been talking about something else.”

“Tony’s also not doing so great with errors.”

“Right, they keep spawning, but he clears them fast enough to be functional.” Bruce shook his head. “This is—if he can walk and talk, one of those ten billion times he should have been able to find the problem.”

Steve reached for patience. “Bruce, if you’re going somewhere with this you’re going to have to just tell me.”

“I’m starting to think there’s not a problem with it. Both of these are... correct. Viable proofs. The contradiction is that they work at all. The most basic proof is proof by contradiction, you would eliminate the base assumptions, but we can’t even do that with these... I think they both... _work_.”

He looked up at Steve, a little helpless, and Steve had no idea why.

“Bruce. I’m not a scientist.”

“A theorem—a _proof_ —in math, it’s not... it’s not like proving somebody guilty,” said Bruce, taking off his glasses so he could fiddle with them. “A mathematical proof takes away all doubt. It’s pure logic. If the logic doesn’t work it’s—then, well, then there’s something wrong with the method, there’s a mistake somewhere—it’s saying two plus two is five, it’s an impossibility. That’s what we’ve got, here. Two plus two is five—it has to be wrong.”

“But you think it’s not?” Steve prompted.

“It _is_ , but, if they both work—if they both _work_...” Bruce trailed off. He was staring at the wall, his eyes focused a thousand miles in the distance. “There’s no error in these proofs. _Somebody_ should have been able to find that by now... but what if it’s not the proof? What if it’s reality?”

“...Reality.”

“You go to extreme examples—the edges of things—math gets weird,” said Bruce, almost rambling now. “Physics gets weird, numbers get weird, if you go far enough. Maybe this is... hah, the logical progression, logic getting weird, going off half-baked. I mean. You said—Tony said—that uh, the Puny God, _he_ said Thanos is going to eat reality. This could be _it_. Or... time travel. Time travel like you described shouldn’t be _possible_. The causal reasons, alone, time loops should be prohibited—transfer of information and matter and energy, it doesn’t—but you said you’d been in a _stable_ time-loop—how do you get _that_ without logic breaking? Cause not following effect; two contradictions existing simultaneously—I think this is _it_.”

“That sounds bad,” said Steve. Reality breaking—well, they knew about the potential for that, already. God above knew he’d seen enough of it himself. Perhaps it was only now sinking in for Bruce; he hadn’t met himself or seen war-torn Maklu or the Infinite Embassy.

“Yeah,” said Bruce. “It. Uh. It’d make all our math suspect.”

 _That_ was new—and bad. “For the portal device?”

“For everything.” Bruce grimaced. “Though especially for working out whether Thanos is still around. I... it might also be why Tony’s having problems? Or he could just be... I don’t know...” Bruce waved one hand, vaguely. “Having problems.”

“You’ll tell him, though.”

“Yeah.”

The lack of recent crises— _physical_ crises, not the constant petty politics that kept spawning more paperwork for him to sign—suddenly seemed unfortunate. Steve squashed the thought as soon as it could occur; it was selfish, and untrue, to boot. But he wished that there was a problem in front of him that he knew how to tackle. What was he supposed to do about math falling apart? If two plus two _was_ suddenly five, would he even notice? Or, if logic wasn’t supposed to work, would he think it had been five all along?

...had it _always_ been four?

 _And this is why you should leave it to the mathematicians, Rogers._ “Great,” said Steve. “He’s probably awake now.”

“Yeah,” said Bruce, but he looked distinctly unenthusiastic. “Uh. With it being... on the internet...”

“He doesn’t actually—he’s not the internet anymore.”

“What, wait—that... sounds like a story,” said Bruce. “No, I mean... Google’s offering a hundred-thousand dollar reward for this. It’s getting noticed, _really_ noticed.”

“But you said it couldn’t really be used for... anything ‘practical’.”

“Yeah, but nobody’s gonna believe reality is breaking down, nobody except conspiracy nuts.” Bruce paused. “I mean, my life is a conspiracy, I don’t count. But it gets more attention and somebody’s going to dig deeper into where it came from.”

“ _Does_ it need to be classified?” Steve frowned. “If not... it’s your work, Doc, you choose.”

“Half of it’s Tony’s.”

“Oh.”

“Yeah.” Bruce made one of his small smiles, the fake ones. “I... he might be pissed it’s out on the internet. I don’t... I can’t really... tell, these days. With him.”

Steve sighed. “It’s already done, though.”

“Yeah, but I... it’s not like he has a leg to stand on,” Bruce said, in a rush, and looked determinedly at first the floor, then up at Steve. “He doesn’t, right—I get that, okay? This is—terrifying, mind-boggling. I can’t even wrap my head all the way around it, I feel like I’m looking at the grand canyon from a distance... seeing it and not really seeing it, and he’d—he doesn’t have a leg to stand on.”

“Bruce.”

“Yeah?”

“Get some sleep. Then tell him.” _Please. He needs a friend who can follow along with what he’s thinking when it’s science._

“Yeah,” Bruce said, and sighed.

 

* * *

 

“I know,” said Tony, when Bruce had finished explaining about the Google prize. He kept his expression calm, thoughtful. It was easier to do than it would have been if this was the first time he’d been confronted with this—but he’d already done his freaking out last night, while Bruce was sleeping.

“You know,” said Bruce, looking relieved. “Oh. Uh—the internet, hey?”

“Yep,” which wasn’t entirely a lie, because he had gone looking over it last night, data rolling out before him like a feast. That he hadn’t thought to look before his subprogram pinged that Bruce and Steve were talking about him— _that may be a bit too stalker-y_ —wasn’t really relevant. And, anyway. Eavesdropping then let him have this conversation sanely now, on his feet. If they really wanted to have private conversations, they knew well enough to have an AED on.

Walking those ethereal pathways, seeing the most brilliant minds in mathematics likewise stymied, had been a revelation; he’d curled up inside a cocoon of extremis and struggled to _breathe_ , for a while, the removal of the weight throwing him off-balance, leaving him teetering. It shouldn’t have been such a relief—those oh-so-brilliant minds had only had _weeks_ to work on the problem. The Millennium Problems had been around years, decades, with only one solved. And, really, if it wasn’t a fault with _him_ then it was an even worse problem, a fault with the fabric of the universe itself. There were enormous benefits could come from the practical application of being able to overlay Reality—and if this was real, if he really _could_ use it to get from A to theta, it might just give him the edge he needed over Loki—but those weren't going to count for anything if the universe fell apart first.

It was still a relief. And in the hours since, error recurrence had decreased by 72%, which probably proved some of Kafka’s more annoying theories about their development, but... progress was progress. He’d face up to it and take what he could get.

“Right,” said Bruce, awkwardly. “That’s good.”

“Yeah, no, that’s—thanks for telling me,” Tony said, the words stilted. Even if Steve had had to convince Bruce to come up here and say it to his face, it was still—progress. _Take what you can get._

“I should have asked, before putting it up,” said Bruce, more mystifying but still awkward. “I didn’t figure you’d care about publishing but—uh, you know. Should’ve asked.”

Tony stared at him, bemused. “It’s fine. I trust your judgment. Better than mine.”

Bruce shrugged again, shoving his hands in his pockets. “Yeah, well. Still yours. I’ve had enough research confiscated over the years, I try not to steal it from other people.”

Tony couldn’t help it; he laughed. “In the wrong division for that, Jolly Green—I stole all this stuff from aliens.” He gestured around—not just to his lab or the extremis cabinets that now took up half the floor-space, but to SWORD as a whole: the Gaterooms below them, the Makluan reactor plant in Bunker Three... “Didn’t bother getting credit.”

 _Mistake._ He knew it was a mistake as soon as the words were out of his mouth. Bruce’s expression went just a little more fixed, a little more distant—

“It doesn’t _matter,_ ” Tony tried, scrambling. _Mistake!_ “ _I_ don’t care what the hell you do with those equations, and I really don’t think the Makluans give a damn—they’re dead, they don’t get a vote anymore.”

“That proof is still your work,” said Bruce, sounding annoyed now.

“So? Bruce, I—help me out here, I don’t get it.”

Bruce pulled his glasses out but didn’t put them on, just fiddle with them. Bad sign—nothing Hulk-related, but still not good for Tony. “You used to get all possessive about this stuff. Whenever we worked together, you always wanted to build, bigger, better, and you wanted your name on it—and mine, too, you kept filing _patents_ for me. But I guess that was just the crazy talking. Sane you doesn’t actually care. Or maybe you’ve just—seen enough, out there. Lost the wonder.”

Tony closed his mouth, and said nothing. He didn’t know what to say.

“Come on, Tony. You’ve always got an answer. Give me an answer.”

No green. Bruce was irritated. Maybe a bit sad. Somehow that was worse—rational disappointment. _He’d be right. Except for—he’d be right._

“It’s not that,” said Tony, pushing his chair away and folding his arms over his chest. Defensive tell—but, that was fine; let Bruce see it. “It’s not. Look at it this way: what do you think we’re going to find on those other worlds?”

“I don’t know,” said Bruce, which... was not quite what Tony had been expecting. “That’s the point of looking.” His mouth twisted downward. “And why the Council’s short-sighted for not letting us follow up on more of those alien worlds.”

“Steve’s working on it.” 

_“We don’t need_ another _vastly superior enemy, and there’s no guarantee they won’t be_ ,” had been the Council’s response to that idea. Rather short-sighted, Tony thought. But it meant that the Council was nixing surveillance of civilizations too far advanced from their own. _“Too much chance they might look back, Rogers... and then what?”_

Steve would wear them down. He’d managed to wear Tony down, after all.

“Steve wants to find weapons.” Bruce shrugged. “You know this won’t be won by weapons.”

“Subspace teleporters, spatial disruptors, interference to cancel out Thanos’ influence, time loops and vertices, black mathemagic... you know the scale of this guy, Bruce,” Tony murmured. “We’re not high enough on the Kardashev Scale. We don’t have time to get there. You have to know this.”

“Sure,” Bruce said, easily enough that Tony raised his eyebrows, surprised. Well, Bruce was just as smart as him, after all. “But I figured, every time I’ve thought something was impossible, hopeless, there you come along with all your optimism—fine, I’d give it a go. You just proved impossibilities a couple weeks ago, you came _back from the dead._ ”

Tony felt his mouth twist. “Sorry to disappoint.”

“So you’re just. Resigned.”

“I promised Steve I’d try.” He laughed, and it was hollow. “Fury, too. But they’re not—they don’t really get it. They don’t get the scale. You’re smarter than that, Bruce. You really think anyone powerful enough to stop Thanos hasn’t already tried? Or hasn’t at least _noticed?_ The Living Tribunal was supposed to be the nearest thing to a capital-G God, and it failed. Who gives a shit who came up with what idea? That’s for history, and there’s not enough of that left to matter. There’s now and then nothing.”

“...You really think that.”

“Maklu couldn’t hold him back. Humanity’s like a... a pebble, to them. Grain of sand.” He grinned crookedly up at Bruce. “End of the world’s coming. How d’you want to spend it?”

“Stopping it,” said Bruce, very evenly. Emerald sparked behind brown eyes.

Tony tilted his head, watching. For a moment, Bruce’s breathing went raspy, and then it smoothed out again. Bruce clenched his hands into fists—and relaxed them, deliberately, one muscle group at a time.

“Excuse me,” said Bruce, and he turned on his heel and walked out.

Tony thought the door closed behind him, and went back to twisting his own brain into knots.

It only occurred to him two hours later, when he was watching Bruce awkwardly relay the conversation to Steve, that he really should have realized that Bruce would tattle.

“Don’t say it,” Tony told Steve, when Steve showed up at his door.

Steve held up his hands, faux-innocence. “What am I not saying?” But there was an edge, there, underneath his words—

_he wants a fight then he can have one_

_no_

The conflicting impulses trapped him; he lagged as the debugger dealt with the sudden spike in errors, and it was enough of a pause for Steve to start speaking. “So I had a conversation with—”

“—Bruce, yes, I know—”

“—which I’m really glad you did, but I wish you’d tell your therapists. They could help.”

Tony blinked at him. _Mixed signals much, Steve?_

“I have been there,” Steve said softly, “thinking it’s impossible. We all thought it, during the War, there were—bad times.”

“This isn’t thinking,” said Tony. He found himself a bit blank with surprise. First Bruce and now Steve— _your priorities are screwed up, kids._ “This is logic. I’m not saying I’ll give up, Steve.” _Just that it doesn’t actually matter._

“Is this... why you don’t want to see Pepper?”

His heartbeat ticked up—sign of stress, impending panic. Tony took a breath and tried to stave it off. “It’s not. It’s. She was—out. She had money. She should—spend her days on a beach, somewhere. I’ve fucked things up, so much, but this—I can’t—”

 _I shouldn’t have told Bruce._ It occurred to him that he didn’t actually want to win this argument. Steve... didn’t deserve to be convinced. As much as anyone deserved anything—let Steve keep his optimism.

“Future’s never certain, Tony.”

 _Just let it go._ “Sure,” Tony mumbled, turning away. He’d already pushed his chair against the cabinets—he couldn’t push it any further back without actually engulfing himself in extremis. If he did that now, though, Steve would probably stand around for hours with a disappointed look on his face, waiting for Tony to come out. Or, worse, would just start talking to him without him there, forcing him to either listen or stop paying attention to the security feeds. “Fine.”

“Hey. Tony.” He didn’t need to look up to see Steve crossing the room, stopping beside him to put a hand on Tony’s shoulder. The security cameras watched for him. “It’s not over ‘til it’s over.”

He wished he could believe it.


	7. Shield and Sword: 1.7

The next few weeks were exercises in frustration. Tony reduced the error recurrence by a measly 12%, watched Steve wrangle the Council into starting surveillance on a few _slightly_ more advanced worlds—about time, since they couldn’t send an ambassador to a world not advanced enough to build a portal to _return_ said ambassador—and nudged the Gateroom teams into noticing data that pointed out that three of the worlds on their short-list were, in fact, on the verge of world war (one nuclear, two more advanced than that) and probably bad choices for dropping into with interplanetary politics. Two others got struck from the list independently.

Steve dragged him out to Central Park two more times, which was somehow nice despite making him feel like an ill-behaved dog needing walksies. The third time, Tony refused. It took him four hours to sort out the resulting error spike, but, afterwards, he found that Steve had left coffee outside his door, in a special thermos, even, so that it was still hot. The fourth time, Tony had just finished trashing the latest restructure model for his brain, and said yes without thinking.

A consortium of other tech companies matched the Google prize. Tony took a break from trying to fix his head directly and went back to the ‘proofs’, combining theories about numbers with theories about Reality and the Gap. Testing it was a no-go, sadly: if the math really did work then he'd get travel through the Gap, but if they were all just missing something then odds were in favour of destroying the solar system instead. But if there was one such impossibility, there had to be more. Could he _actually_ prove that two plus two was five? When he did a review of what other people had done, though, he found that he'd been beaten to the punch. Their new field was expanding. His head filled with impossibilities, and for four days straight he sat applying them to his own neural networks instead, programming extremis until finally, his eyes aching with fatigue, he switched off the debugger... and nothing new glitched. Immediately.

If the math wasn't proven beyond doubt yet, something about it must still be close enough to reality—or unreality—for approximation. He spent the rest of the night programming other impossible features, watching extremis reconfigure itself, until a sour taste began to dance on the back of his tongue, one he could almost recognize as _hope—_

Loud knocking woke him; he jerked awake and half-fell out of a cocoon of extremis. _When did I fall asleep?_

Sleep mode start time: 07:08:11   
Sleep mode end time: 11:31:49   
Errors in quarantine: 32 

Security feeds snapped into his head, and Tony scrambled to his feet. Foster was standing outside his door. Even as he watched, she raised her hand again, and he triggered the door release and it opened beneath her fist. She pulled back immediately.

“Oh,” said Foster, startling, and then pushed the door open, peering into the darkness. Right. _Lights_

They blinked on. He was somehow more aware of the harshness of the fluorescent glow when it was Foster standing there. She really was a tiny woman—and she was holding something odd in her hands. Tony opened his mouth to speak, to say... something, and found that his throat was too dry.

 _I thought I fixed that._ A subroutine assigned the debugger to hunt down the problem.

“Hi,” said Foster, after a moment. Tony shut his mouth. “Look, I, uh, think we didn’t get off to a very good start.”

blood already bubbling around her lips. Punctured lung 

Tony nodded, warily.

“So, I thought... look, I’m not going to _apologize_ for yelling at you for stealing my research, because you had that coming, but, I get it, you were, um, you were having a bad time and I can get that, especially bad times with people watching you or whatever, because—well, SHIELD—okay, moving on,” she said, her words gaining momentum the more she spoke and her hand gestures getting wider, if not any more articulate. Tiny, but she had more than enough energy to make up for it—or she was buzzing on a caffeine high and no sleep; that was also possible. Tony flashed back through the records.

He hadn’t been keeping much of an eye on her. Avoiding her—

This time, he managed to stop the memory before it started to play out in all its gory detail. It hovered on the edge of his consciousness instead, ominous memory...

_Door’s already open you’ll see him coming_

_No, STOP_

“—this is part of the spatial research but it’s a prototype, at least. I thought maybe I could demonstrate it and then—”

Eyes on the exits. His mind suffused the security system. He tracked every person in the building, every shift in the weather patterns outside—this room was shielded from Asgardian sight, but if she said the magic word... and wouldn’t she?

_face it stark you had it coming_

Guindi, Shahir checking Monroe, Delilah for a concussion. Walters, Dan, welding bridge mountings in Gateroom B. Rogers, Steve, tapping at his headset, asking, _“Tony?”_ and making a beeline for an elevator. Lewis, Darcy, wandering down the hall outside his lab, a Starbucks in each hand. Li, Yong identifying her by face and badge, information popping up on his tablet as she approached.

“—not applicable because they were _sound_ waves, but that actually only matters in the macro-scale, whereas this—”

Everything Foster was saying was rushing up on a sea of white noise. The debugger returned with no errors found—no problems with extremis. _well at least it’s keeping itself on the wet half today_ He reallocated the processing space to downloading all of Foster’s notes and simulations on the thing she kept waving around, since it was probably important. Processing would have to come later. Right now he was busy trying to remember to breathe.

It shouldn’t take so much memory to do that.

“Yo, Jane,” said Lewis, sticking her head through the door. “And... yo, Mr. Stark. Uh.” She stopped near the open door. Her eyebrows were creeping up her forehead.

“Um,” said Foster, turning slightly. Tony didn’t quite manage to suppress a twitch at the movement. He did successfully suppress coating himself in bulletproof armour, though—small accomplishments.

_Would it do you any good?_

“I was just explaining, to Tony, I thought he’d be interested—” Jane held up the Silencer.

“That’s... great,” said Lewis. “But I got coffee here and I think Bruce wanted your opinion on some readings, like, right now.” She stepped closer to Foster, within arm’s reach, and handed her a coffee. Foster took it without question, and Lewis took the opportunity to grab the Silencer and place it back in Foster’s bag.

Security records showed that Lewis hadn’t been anywhere near Bruce, or received any communication from him, for the last forty-nine minutes. Tony took a step back toward the cabinets and shoved more processing power into tracking her. His nerves were singing with the threat— _no. no can’t be, not the same_ —and then Steve’s elevator arrived and he was jogging down the corridor—

_oh god if i fuck this up steve’ll_

_Fuck_

He pulled the illusion and armour around him in the same moment, running through commands to deactivate weapons, deactivate subspace access, no matter how much it made him cringe. Crippling himself—doing this meant it would take a moment longer to bypass those deactivations and if it came down to it, that would be too long—

“Er, okay, I’m sorry, I’ll go,” said Foster. “Just—you know, if you want it, there’s the research—but you have to credit me.” She was frowning and

“Anthony Edward Stark. I find you guilty of regicide.” 

But it wasn’t Thor standing in the doorway, it was Steve. Instead of homicide, there was concern in his expression.

 _“Sure,”_ Tony made his speakers say, making them sound like him. His actual throat was too closed up.

Lewis lit up like Christmas on seeing Steve. Somehow it felt like a betrayal even though _they’re not working together it can’t be stop being an idiot god fucking damn hell_ She linked her arm through Foster's, juggling the coffee as she practically dragged the other woman toward the door and Steve. “Captain! You have great timing. Jane was just saying about how she needed to talk to you, super exciting discovery, right, Jane? So we’ll just take this outside—”

“I was? Um, I mean, yes, it’s great, but—”

“Yep, and now’s a great time to discuss it, before you get bogged down—” Lewis kept on, pulling Foster into the hallway and onto a different set of cameras. “Uh, and, Captain Rogers, it would be really cool if you have a moment to listen—”

Steve paused her, holding up a hand. Foster was eyeing Darcy, half-smiling the smile of someone trying to appear casual in front of their boss, but as soon as Steve turned away she hissed, “Darcy, _what_ —”

“Trust me, trust me,” Lewis muttered back.

Steve must have been able to hear every word. He gave no indication of it, looking toward Tony—the illusion that was Tony—and staying in the doorway, a blond giant. “Tony? You sounded—”

He’d sounded—what? Tony didn’t want to find out. When had he called Steve? _god fucking damn it_ _“Go,”_ he told Steve, radio only.

Steve frowned. “If you’re sure—”

Tony triggered the door fast-release. Steve stepped back before it could whack him in the face, and Tony let the mag-lock click into place with enough torque that Steve had to hear it.

Extremis was behind him, all around him... but it was just as vulnerable as any frail human. _He_ was just as vulnerable. Tripitaka had ground him into the dirt, had crippled him to the point where extremis had barely functioned. Loki would do the same. Thor would do the same—had done the same—would do the same. They were all alike. They were all gods and monsters. 

Humanity had no goddamn chance.

 

* * *

 

“Darcy, _what are you doing—”_

“Right. Okay. _Captain America_ , and I am making a great first impression because this is my life, but okay, I’m sorry I forgot to bring you a coffee but here you go, Yong, you like French Vanilla, right?” Barely pausing for breath, Lewis handed off the coffee in her other hand to the bemused agent, and kept on trying to shepherd Foster down the hall towards the elevators. “So we need to go get—more coffee. Outside. Right? Government commissaries never have good food—”

“SHIELD usually does, Ms. Lewis,” said Steve, keeping his voice calm. Lewis looked flustered, and young, and half on the edge of frightened panic. But determined panic. This was important, whatever it was—important enough to leave Tony. Tony had called him down there in the first place, and even if he was panicking, he’d told Steve to go with her.

“Right, if you like, like, _insects_ in your coffee, but I know this great place outside and I think Jane—”

“Oh my god, you are not _talking_ for me,” hissed Foster, flicking glances between Lewis and Steve. “Captain, I’m sorry, I don’t know—”

“It’s fine,” said Steve, putting just enough authority into it to silence them both. “Where would you like to go, Ms. Lewis?”

“I don’t know, _not here_ ,” said Lewis, and Steve nodded, taking the lead as they headed to the elevators. There was a swiftly whispered argument behind his back, which he pretended to ignore.

“What is _wrong_ with you?”

“What is wrong with _you_ , are you seriously that oblivious—”

“This is my boss, this, this is _Captain America_ , you can’t just—”

“I’m sure your boyfriend thinks that’s _hilarious_.”

“Oh, please, like that’s what this is about, you’re not doing any better—”

Lewis visibly relaxed as soon as they were out of the building, which just made Steve tense up further. What had happened back there? Fortunately, the usual place Steve got coffee for Tony at was less than two blocks away, and since it _was_ his usual place, the barista didn’t bat an eye at them even though Steve was openly carrying his shield. They settled into a table at the back and Steve pulled out his AED, clicked it on where the two women could see it, and then put it back in his pocket.

“If you’re looking for privacy, Ms. Lewis, we’d be better off having this conversation back in the NYHQ.”

“I’m not worried about _privacy_ , I’m worried about _murderbots_ in the walls, Christ,” said Lewis, taking a long drink of her ridiculously complicated coffee order. All the caffeine and sugar actually seemed to make her calm down, though. “This is—no, okay, privacy, good point, Jane, you got the thing?”

“Yes, I have, but what are you about _murderbots_ —” Foster pulled something from her bag, a boxy gadget about the size of a Rubik’s cube, and set it on the table beside the AED. She tapped a couple buttons on the side, and the world became strangely... quieter. Steve could still hear things, but...

“What is that?” Steve asked, sharper than he’d intended.

Foster immediately looked flustered. “I haven’t named it yet, it prevents transmission of the—” she looked between Steve and Lewis and sighed. “It makes it so Heimdall or Loki or whoever can’t overhear us from across realms. I mean, in theory it’ll work on close range eavesdropping, too, but I’m still working on the calibration. I was hoping Stark would help with that, he’s got more experience in—”

“No, this is not okay,” Lewis interrupted. She pointed at Foster, but was looking at Steve. “She can’t be in the same room as Stark. Not alone, it’s not safe!”

“Darcy!”

“He’s a mentally unstable dude who can probably _literally_ kill you with his brain, and he is _scared_ of you. You need to stay away from him!”

“—I—I might have been a bit mean to him when we first met. I’ll apologize—”

Lewis let out a groan of frustration. “Jane, I know we joke about how scary you are if somebody gets between you and coffee, but this is different. This is somebody being _actually terrified_ of you. You!” She fluttered her hands in Jane’s direction and looked at Steve. “Her!”

Foster was pretty petite, Steve had to acknowledge, although size wasn’t the best indication of lethality. Her air of academic haplessness, however...

“That doesn’t make any sense,” said Foster. “Why would he be scared of me?”

“Because he’s _crazy!_ ”

Or because Tony was scared of _Thor_. Tony didn’t trust Thor—hadn’t since... since when? Had it been since this had all began, when he’d fallen through that portal—before that? He’d seemed to get along with Thor well enough at the time. But when Steve had called Thor an ally, Tony had refused to consider him as one. And true enough, maybe they didn’t know his—whole self—well enough; they only knew the Thor on one world. But there was a difference between not knowing and being scared of someone, specifically...

“He’s not _crazy_ , Darcy, you’re completely over-reacting!”

“No, you’re not _looking_ ,” Lewis accused, and then jabbed a finger at Steve. “And neither are you! Look, my college roommate’s ex-girlfriend, we used to hang out all the time, and then she got a new boyfriend and started getting all weird because the guy did shit that deserved jail time and eventually she had a nervous breakdown and had to move back in with us and having two exes in the same apartment, wow, awkward.” It would have been impressive how she didn’t breathe while saying that, but Steve was more concerned about her apparent returning panic. “And she? Looked _just_ like Mr. Crazy back there. Same twitchiness, same retreating across the room, same fixated stare of panic—except, y’know, she didn’t have a personal body count of either a few hundred or thirteen million or fifteen million, depending on what you include. _And_ she didn’t keep going serial-killer creepy blank-faced when talking to people like he does, so y’know, I get he was your team-mate and you’re probably friends, and holy _shit_ Captain America is friends with—” Lewis stopped, took a breath, and visibly took hold of herself. “But it doesn’t change the fact that you need to make sure he stays _away_ from Jane, and, like, gets therapy or something,” she ended weakly.

 _Therapy. Sure, that never crossed my mind,_ Steve thought, struggling to keep the annoyance off his face. He thought he mostly succeeded.

Her observations were worrying, though. So Tony was scared of Foster specifically. But why? Even if he had something against Thor...

“Has he ever sought you out?” he asked Foster—mostly for Lewis’ benefit, as he already knew the answer. Seeking her out would have required Tony to leave his lab.

“No-o...”

“In that case, the easiest way to prevent you being in the same room with him is—” Steve broke off, as the barista approached, a tray of pastries in hand. It wouldn’t be the first time he’d gotten an extra on his order in this cafe, probably because he always tried to tip well. Steve smiled up at her as she set the tray down. “Thanks, Janine.”

“No problem,” Janine said breezily, and then she drew up a chair from the empty table nearby, settling into it and grabbing a pastry for herself. “I just _had_ to put in, sorry, I don’t think therapy’s gonna help him. Last time I saw him—but you can’t blame this on me. He messed up his brain all on his own, pretty crazy.” She twirled a finger in a circle beside her head. Her eyes were very green.

Janine’s were brown.

“Shit, we have coffee agents,” Lewis muttered, rummaging in her enormous purse, but the next moment, her head snapped up as Steve asked, “What do you want, Loki?”

“Ohmigod,” Foster half-breathed, half-squeaked.

The AED was in his pocket. He could probably manage to turn it off without Loki seeing, but Foster’s device was right on the table...

“Well...” Loki drawled, still wearing Janine’s skin—oh, Lord, where was Janine?—“ _Existentially_ and historically, my desires are rather ironically governed by my position, but in the short term—” he shrugged, his eyes glittering with cruel malevolence that looked horridly out of place in Janine’s face. “I couldn’t help but be intrigued when you went so silent. Although I _had_ been planning to pay you a visit anyway, to see if you might be of use in convincing dear Tony to cooperate. It’s only the fate of the entire multiverse at stake, after all. And, being that this multiverse is my _chosen_ home, I find I’m rather more attached to it than I was to—”

Lewis’s hand snapped up from her purse, holding something that Steve had time to identify as not a gun just before she fired. There was a flash of green light, and the taser probes deflected wildly and rebounded on Lewis, instead, hitting her in the face; she gave a choking scream as her limbs spasmed wildly.

Steve was already moving, grabbing the end of the table and flipping it sideways into Loki’s face, then turning to try to rip the wires away from Lewis—the current was causing all her muscles to convulse, and she didn’t look entirely conscious anymore but her finger was still locked on the trigger. Before he could reach them there was another green flash, and he had to roll to the side to let the shield on his back intercept it—except that didn’t work, as a wave of green from a different direction smacked him away from Lewis and right through the wall of the cafe. Steve pulled his limbs in and rolled with the motion, letting his momentum bleed off, and nearly got run over by a car. Horns blared; tires screeched; one car pulled to a halt at an angle that obstructed the street; another ran into a street post. The pop of airbags was loud. Steve flipped to his feet and pulled his shield from his back, raising a hand to frantically motion at the drivers who had stopped, tapping his comm on the way. He clicked the AED off. “Get out of your cars, and run!”

_“Sir?”_

“Loki’s here. Get Banner, Stark on the line—” Not a winning combo, if what Tony said about this Loki’s level of power was true, but it was the choice between heavy hitters or no hitters at all.

_Tony. Sorry._

The large hole that Steve had made in the shop wall blew open wider, and Loki stalked out, dragging Dr. Foster after him; he had one hand around her throat, the other full of crackling green magic, and he was wearing his usual form with full regalia, now. Steve threw his shield on a ricocheting trajectory and dashed forward, diving over the bolt of magic Loki sent his way and coming in low. Loki leapt backward, up into the air... and stayed up there, green power swirling about his feet.

He could fly. Of _course_ he could fly. Anthony had flown in the same way.

 _“Stark’s put his lab on lockdown.”_ That was Hill, good—and, at the same time, _shit_. _“We’ve got reinforcements on the way—”_

Steve sprang upward; at the same instant, his shield came down at a hard angle and slammed into the back of Loki’s knee. Loki buckled, dropping Foster—Steve couldn’t alter course to grab her, and she fell hard to the ground below, where she lay coughing and wheezing. Steve grabbed at Loki’s foot, and shouted as his hand passed through the magic green cloud. It felt like it was sandpapering his skin off. But he managed to get a grip for long enough to yank Loki with him, back to earth—and then gravity rebelled and more green sent him flying into the grill of a car.

He bounced off of it and rolled to his feet, snagging his shield as it came down again. Loki was already standing, and smirking at him. “You’re very good,” Loki purred, materializing long knives in both hands. Steve eyed them warily. They looked a hell of a lot more lethal than that sceptre, and he’d seen what that could do.

Loki rushed him.

The training that Steve had had over the past year was all that kept him in the fight for more than ten seconds: Loki was _far_ more skilled with knives as weapons than he had been with the sceptre. Or maybe this Loki was just a better fighter, flat-out. Steve didn’t have the slightest chance of going on the offensive; he kept his shield up as much as possible, blocking blows and dodging those he couldn’t. It wasn’t enough—he couldn’t keep up with such alien speed—

The quiet roar of a quinjet skirted at the edges of his hearing, and Loki backed off, disengaging just long enough to form another green bolt and shoot the invisible jet straight out of the sky.

Shit. Where was Tony? Where was Bruce?

“I think that’s enough, don’t you?” said Loki, and abruptly Steve’s hands snapped behind his back as his feet were dragged together with enough force to break bones, had his not been enhanced. He managed to keep his balance—barely—but with another casual gesture, Loki knocked him to his knees. The shield was still on his arm; Steve tried slicing at the energy binding his feet together, but it didn’t have any effect. “That’s better.”

“What the hell are you trying to accomplish?” Steve spat at him.

“A number of things,” Loki said vaguely. “And, I _admit,_ I was just going to take you...” He snapped his hands up and a magic shield blossomed into place, a green dome sitting over them like a bubble, just in time for Steve to pick up the roar as the Hulk descended toward them at speed. Enormous green feet hit the shield right over Loki—Steve frantically tried to roll away from the wreckage sure to follow—and the shield bent inward, like rubber, and then flung the Hulk away in the exact same direction he’d come from.

Loki continued on as though he hadn’t been interrupted. “But since Jane is here—she wants to see the multiverse so badly.” Another snap of his fingers, and Foster was in his grasp again, struggling weakly. Loki smiled down at her. “Shouldn’t we oblige her?”

“Let her go!” Steve shouted, but Loki just smiled wider. “It’s not her you want!” Steve could hear the Hulk roaring in the distance—he wouldn’t be gone for long. The Hulk might have a limited number of objectives, but he wasn’t stupid, either. Given time, he could probably break Loki’s shield. “Whatever you’re trying to do here—”

“I am trying to save the multiverse,” drawled Loki, and the shield around them collapsed inward. “It’s not my fault you have no _vision_.”

The green light hit Steve’s skin, and the world fell away with a sickeningly familiar sensation.

 

* * *

 

The door to Tony's lab blew off its hinges.

Security overrides dumped Tony out of coding and back into his skin before the ex-door was more than an inch out of its frame; he was on his feet and in the armour by the time it hit the floor. Weapons were already ready to fire as sensors registered that beyond the door was Hill (standing down the hall, out of the line of fire—smart woman—but that was her finger on the trigger for the carefully set explosives that had blown off the door) and... no one else except an ashamed-looking Li. No TAC squad. No Steve.

 _“Hill, what the hell?”_ he asked after a moment.

Cameras, and other sensors, showed her marching down the hall, through the dust caused by her controlled demolition, to stand in the doorway with her hands on her hips. “What the hell have you been—” She cut herself off. “Rudolph grabbed Rogers and Dr. Foster out of a cafe six minutes ago and teleported away.”

Tony felt his insides turn to ice. Balance wavered precariously; he grit his teeth and somehow managed to hold on, to shove away the urge to override it all and make it all go away. He cast his mind outward, instead, downloading all the data available—from cameras, phones, satellites—tracing Steve’s path out of the building. He was stymied after they got to the coffee shop—of course; Steve would have anti-eavesdropping tech on him—until Loki blew a hole in the side of the building and took the fight outside.

Fight. If it could be called that. God, Steve put up a good defence, but Loki was toying with him—a fact made obvious when he took him down so easily with magic, repelled the Hulk, and then vanished with his hostages.

 _“I’m going,”_ Tony said, brushing past Hill.

“About damn time,” she growled, whirling to follow him, and Tony nearly stumbled again. Loki had Steve. “You’re also classified, so if I _see_ you on camera—”

_loki has steve_

He’d just grabbed him. While Tony was sitting uselessly on the floor, trying to dig through his own _fucking_ head—if he hadn’t been so goddamned—

_have to get him back_

He went invisible halfway down the hall and ducked into the emergency stairwell, taking advantage of the clear middle to rocket up to ground floor. _There_ it was crowded, SHIELD personnel running every which-way, nearly colliding with him unless he moved out of their paths. The delay gave him time to think, to call up other protocols and redirect satellites on the fly. Several million TV customers were going to be pissed, but that was what they got for not having switched to cable, already. Tony needed everything he could get his hands on, and commercial satellites were going to be easier to explain away than military ones. If Loki was still on Earth—Tony doubted it, but he had to cover the possibility. He reached the doors and was gone.

_he took them both alive that means something he was making a show again what was his point this time_

It was more of a hop than a flight to the cafe, which was surrounded by cop cars, ambulances, and two fire trucks—although his data feeds told him that the total casualty count had been low. The barista had been found lying behind the counter, completely non-responsive; she was being secured for transport to SHIELD medical along with Darcy Lewis, who had apparently been electrocuted with her own illegally-upgraded taser until the battery had run out. There were no other reported injuries more serious than a sprained ankle.

Clint was already here, standing off to the side and talking soothingly to the Hulk, who was intermittently punching the ground, causing small tremors and making everyone else wobble, but, Tony noted, causing no additional structural damage. A small perimeter had been formed, not just of agents, but police officers as well, standing with their backs _to_ the Hulk: they were there to keep other people away, not to pen him in. Barricades of cops were forming at both ends of the street as traffic jammed up for blocks around, a rapidly cascading effect that would probably shut down New York for the rest of the day—if not the week, depending on how this spun in the public eye.

Eight months ago Tony would have dropped in and taken Clint’s place in talking to Bruce. But Clint had it in hand, just like Hill had the rest of the scene in hand, so instead Tony invisibly hovered a few dozen metres above the street and set every sensor he had into looking for _anything_ , any clue about the method Loki had used to get away or where he might have been going.

If only he knew what had happened inside the cafe— _shit. shit shit shit_ Why had Steve needed to use the anti-eavesdropper? _god damn fuck_

Three people had entered the cafe; Loki had vanished with two. Why _had_ the three of them come here? Cameras back in the NYHQ told him it was Lewis’ suggestion—more of a demand. He opened a direct line to Hill. “What’s Lewis’s status?” There wasn’t sufficient camera coverage in medical.

_“Stand by.”_

He kept the line open, although she clicked her mic off; he could hear her giving orders on other channels. When the reply finally came back, he heard it a millisecond before she did—his ears, long or short-range, were more efficient than hers. Lewis was barely responsive, her brain waves were all over the place, she was suffering almost constant micro-seizures—she’d be lucky if she ever regained consciousness, and luckier if she wasn’t severely brain-damaged from it. “Got it.”

Shit. That was no help. Loki had Steve—and Foster. If he’d _just_ taken Steve—

_no reason he can’t kill two birds_

But Loki was already doing that, wasn’t he? “I am trying to save the multiverse. It’s not my fault you have no _vision_.” Motivation—a hostage crisis; Loki had already _told_ Tony what he wanted him to do... and beyond that, if Loki had any idea, if he tried to get into Steve’s head...

But why take Jane, too? What did that get him? Leverage over Thor?

The energy field that Loki had left behind when he’d made his exit was swiftly decaying. Useful data slipped through his fingertips even as he attempted to record it, and too much of it was already lost. The fading configuration told him it was probably a portal off-world, but trying to pin down where it had gone was like trying to enhance an image of only four pixels: the data just _wasn’t there_. If only he’d had sensors out here when it had happened—but he hadn’t. All the satellites he had _now_ weren’t helping him with that.

But they did let him know immediately when Thor hit atmo.

“—recently appointed Deputy Director of the newly-minted Special Weapons and Ordinances Regulatory Division—” 

“—not responding to anything, Director, I don’t know what—” 

“—fight was taken out into the street. There’s no word at this time on the identity of the woman who was taken along with Captain Rogers—” 

“—regarding the ability of SHIELD to deal with—” 

The American media machine had woken up; #brooklynbattle had emerged victorious over #capnapped. Tony teetered on the brink, extremis giving him more data than he had memory to process. If he let himself dissociate, borrowed space elsewhere, it would be easier than staying anchored to flesh and bone—

 _More dangerous_ _,_ he reminded himself. His core programming remained with his brain, no matter what it _felt_ like. If he split from it he might not be able to pull himself back together. If he lost it _now—_

Thor landed with a crash of thunder that echoed across the clear sky. Smoke rose from his cape and his golden hair was dishevelled; he'd emerged not from bifrost, but falling out of a hole ripped in the sky, and it closing was the thunder-crack, not Thor’s landing. He hadn’t even broken the cement. Thor pulled himself up straight and looked to Clint and the Hulk, without so much as a glance up at where Tony hovered. Hovered, still, because he had... maybe gone a bit blank, there, but at least he hadn’t freaked out completely and crashed, or lost invisibility, or taken out the local power grid. Small victories.

_Really fucking tiny ones._

The Hulk growled, a sound that shivered the air until even Tony, encased in armour, could feel it rattling his skull. Clint, showing even less common sense than Tony had previously given him credit for, stepped between them, hands up in a ‘look, no arrows’ position, talking really fast to the Hulk. It worked, and the Hulk backed off, growling, then finally began to shrink back down into Bruce.

It shouldn’t have been such a surprising sight. Clint had basically been Bruce’s personal pilot for the last few months, and of course they’d become friendly. It made sense. It was good that Bruce had somebody to offer him clothes and food immediately.

There were people everywhere, but one of the parked quinjets provided enough cover; Tony let himself drift over to it and then down, landing with barely a thump or a thud. Hidden in the shadow of the jet’s wing, he switched the ICG into imaging mode, picking out the look of a tall, heavy-set agent with dimensions similar to the armour. The image switched seamlessly. Even if anyone _had_ been watching, all they’d see would be a SWORD agent with either invisibility tech or a teleporter. Which would probably piss off Hill all the same, but today was a shitty day for everyone.

He took a breath. Thor was—standing there. Hammer in one hand—

_end repulsors_

The forced shutdown stopped him just in time.

“ _Now_ you show up?” Clint asked sharply. Tony could hear him easily from this distance, could eavesdrop all he wanted. He only needed to go over there if he wanted to talk to Thor directly—Clint had a comm, after all.

_jesus christ stop being such a fucking_ coward 

His thoughts were too staccato.

Tony took a breath, and forced himself to start walking—tiptoeing, really. He could have reformed the boots to something that didn’t knock so much against pavement, but that would have meant getting rid of the boot repulsors, and he really couldn’t make himself do that. The imager smoothed it over and made the 'agent' look like he was sauntering instead of carefully placing his feet.

“My friends,” Thor said, placing his hammer back on his belt. “It is good to see you, although I regret it is never under better circumstances.” He looked grim, as grim as he had

_STOP_

“What do you know?” Natasha asked, point-blank, stepping up out of—memory files skipped back and located her, although a moment ago he’d have sworn she wasn’t on scene. Or was she just avoiding the Hulk? Tony reached them and stopped a few metres short, illusory arms folded over his chest in one of those ‘I’m a big burly agent, back off’ poses. This was a meeting of Avengers, not the random agent his illusion had him as. But he could play at security, as well as _being_ security. Beneath the illusion, he had targeting locks on Thor.

“That Loki was here.” Thor stretched out his hand. The air pressure dropped, winds picking up and all moving toward him, swirling around him and making that red cloak billow—Tony swallowed and focused on sensor readings, shoving aside the subroutines that had caused extra weapons displays to pop up across his vision. Solid matter began to condense within Thor’s grip, turning into a crystal, one that looked like milky white, low-quality quartz. A chain wrapped around it, and as the winds died Thor tipped his hand, allowing the stone to hang by the chain. It immediately began to spin of its own accord—or was it Thor, doing something? “This is a passage-stone.”

_and that wasn’t quite a subspace pocket._

“You can track him?”

“Aye.” But Thor grew no less grim, although the stone had begun to glow from within, and— _oh hello_. “He must have had aid. He left directly from his cell, and he could not have done so without a bridging device. My brother is wise in the Unseen Ways”—Tony could hear the capitals—“but his cell was carefully placed. There were none near.”

_except—_

Tony focused instead on the lights flickering beneath the spinning passage-stone: a wide series of interlocking circles of runes, too complex and flickering in and out far too quickly to be accounted for by the outer physical motion of the stone. If he allowed himself to imagine that the circles wound into 3D space... once before, he’d seen runes like this and been stymied. But those had been far more complicated, describing a far greater distance, and he hadn’t had extremis, then. He hadn’t even really known what the runes meant, then.

Now he did.

_got you_

It had already been twenty-three minutes. The trail was going to grow cold. But if Loki hadn’t stopped immediately after bridging away from Earth—and, if he knew about the passage-stone, he’d have been an idiot to—then running after him immediately wouldn’t do any good unless Tony could bring the passage-stone along as well... and make it work.

shit. 

“Nice light show. So you can hunt him down again,” said Clint, hands in his pockets. He made a show of thinking it over. “You gonna actually follow through this time, or are you gonna bail again when something else comes up?”

“Clint,” said Natasha, as Thor’s face darkened. Tony picked up another air pressure drop, but it levelled out again without any wind.

“Needs to be asked,” Clint said stubbornly.

“You speak of that of which you have little knowledge. Not idly did I leave you. The battle Asgard fights now is one upon which rests the hopes of not just Asgard, but Earth and every other world as well,” said Thor. “Although I judged it less a risk than allowing Loki to roam free, nonetheless I have damaged Asgard’s defences by cracking the wards to return to Earth; and as I did so against the express command of my king, I am now a traitor and an exile. That is what this is worth to me, Master Archer. I will see it through to the end.”

_well hes still good at speeches when pissed_

Sunlight glinted off of Thor’s hammer, off of Natasha’s hair, off of the lenses of Bruce’s glasses. Distracting.

 _come on stop staring at him like a moron_ —but he couldn’t make himself break the targeting locks.

“Well. Uh. What are we waiting for?” Bruce asked. He glanced around. “It looks like you’ve got your directions.”

“But not transport.” This time, Thor fixed his gaze on Bruce. “I know that Midgard has been seeking such. Perhaps you may cloak yourselves from Heimdall’s eyes, but you cannot hide the ripples of passage, not with such crude bridges as you have been using.” _crude my ass_ _—_ the thought flailed and slipped away as thunder cracked overhead. “I know you have trod roads I warned you to avoid. From these runes,” Thor nodded to the light-show, which was beginning to repeat, “that is well enough. My brother has taken a long road. But if we act swiftly, we may yet catch him.”

_is he lying or does he really not know_

If Thor didn't know, then he was chasing the wrong Loki. So did he know? From the consternation on Bruce’s face, at least one Avenger thought Thor was playing it straight. Natasha and Clint were spies, and it was impossible to know from their expressions. Unless... could Loki help himself, somehow, from across realities? Was that how the one from here had gotten out of his cell? Hell, that was all they needed.

“He’ll have hopped away again, right?” said Bruce, absently taking his glasses out to clean them on the edge of his new, over-large sweatshirt. “He won’t stay in one place if he knows you’ve got things like that.” He used his glasses to indicate the still-spinning piece of quartz.

“He’s not a complete idiot,” said Clint. Thor nodded stiffly.

“The portal machine’s as large as a room,” said Bruce, putting his glasses away again. Without something else to fiddle with, he worried at his thumbs and fingertips instead. “And it’s one-way.”

_come on, SAY SOMETHING_

Breathe.

If he did this—he’d have the bridge. He’d have control of it.

This wasn’t that Thor.

Was it?

“Unless we have another way,” said Natasha, and she was looking right at him.

Bruce turned away, his voice a low mutter. “Of course we do.”

Something in his illusory expression must have revealed him; there was no other way she could have known, not when he'd only finished implementing it last night, and told no one. Before he could think better of it he jacked the code for the illusion around and set it to unnatural stillness. Bruce made a face when he saw it, and looked down, away—pulling himself back? Thor, though, Thor was—

—frowning, but not reaching for his hammer. “What trickery is this?”

The part of Tony that had been watching the crystal's patterns had noticed they’d begun to repeat. A moment later Thor gathered it up, still frowning at Tony.

“Thor, this is our not-so-dead teammate,” Natasha said coolly—and quietly, despite her own AED, Clint’s, and Tony standing there in the armour. Not that they could see that part. “I think you’ve already been introduced.”

The frown turned to confusion. “Heimdall mentioned rumours, when he’d time to speak of them with me, but I thought them false. Tony, I'm glad you live... but I would hear your own answers for those actions you took in Shenzhen.”

 _“I was crazy, I got better,”_ snapped Tony with the armour’s voice. Something in his brain shrieked at having spoken. Breathe—nobody else could see, could know it was more of a gasp. Step forward, push onward. _“Guess who—never mind. You’re planning on coming with us? Who’s going to step out the other side of the portal?”_

“It should be all of us,” said Thor. “Loki is a formidable foe—”

 _“Not what I meant._ You. _You gonna be our enemy on the other side?”_ He wasn’t getting anything but confusion, shaded with restrained outrage. _“You’re not_ like _us mere mortals, you don’t run the risk of meeting yourself in an alternate reality. There’s no alternate you. Just—what was it—‘different aspects’. An all-in-one being.”_

“Ah,” said Thor. “I see.” His eyes narrowed. “But I do not think that you do. When the branches of—”

“We’re burning time,” Natasha interrupted. “Just answer the question, yes or no—nobody cares how it works right now.”

“Uh, I do,” said Bruce, raising one hand.

“I could,” said Clint.

_me too_

He stared Thor down, refusing to let his eyes waver—real or illusory.

“ _I_ am curious as to how you know of this at all,” said Thor, crossing his arms over his chest. For a defensive motion, it looked damned intimidating. “But as time is short, I won't ask—for now. Asgardians are perhaps something more than mortals, but unless our trail goes to the very centre of the universe, the beginning of all reality, then the difference in this regard cannot be seen. I give you my word as your comrade, I will protect you and do you no harm.” His gaze was too piercing—too knowing.

 _“And if we go there?_ When _we go there?”_

Thor’s eyes widened in realization, but he mastered himself again almost immediately. “Then you will still come to no harm, as I have given you my word.”

_aha. Ha._

“Great,” said Natasha. “Can you read those symbols well enough to make a portal?”

 _“Yeah.”_ He swallowed behind the illusion. So... he was actually going to do this? _“I don’t suppose you could just teach me how to use that crystal and stick around yourself to help out here, huh?”_

Thor shook his head. “It is keyed to the royal line.”

_“Then that’s a problem. My portal-device is me-only.”_

“Can’t you make another one?” Natasha asked. “You grow things out of extremis all the time.”

_“...Let me clarify. It’s me-only because it transports things via a direct route through the Ginnungagap, the sight of which will drive anyone not-me certifiably insane. Also, it’s untested, and depends on physics being broken, so it might not work at all.”_

Thor frowned. “I do not fear the darkness of the Ginnungagap.”

 _“No fear of death? You should worry about what it’d make you do to others.”_ That other version of him, standing tall—Tony barely executed a forced shutdown on the long-term memory viewer before it could overwhelm him with images, sounds, _feeling_.

“Extremis protects you,” said Natasha. “Isn’t there some way to protect us?”

 _“Matter doesn’t_ matter _to it,”_ said Tony, rather than risk getting caught up furthering the lie about _why_ , exactly, he wasn’t affected by the Ginnungagap. Steve would agree; he’d kept mention of the Soul Gem away from SHIELD even from the very beginning. _“You need to not be there, to have reality proper between you and—huh.”_

“Subspace,” said Bruce.

_“...I can’t stick a living person in a subspace pocket, the in-out process isn’t friendly...”_

“But it’s possible to overlay subspace and realspace, Foster’s generalized theorem showed that in—”

 _“Yeah. Yeah, okay.”_ Tony licked his lips and ran calculations on the fly. Theoretical. This was all theoretical. He hadn’t had _time_ to test it, damn it. _“Yeah. Okay. You still unafraid?”_

“Yes,” said Thor, but sounded neither quite so certain nor so arrogant about it this time.

 _“Great.”_ Tony looked at Natasha. _“If we’re not back soon... it might not mean anything. Time doesn’t always run at the same rate.”_

“If you think we’re staying behind, you’re an idiot.”

 _“I’m the guy with the portal device—alternate realities aren’t_ friendly _, and none of you has an exoskeleton... unless you can ward them, Thor.”_

“I cannot.”

“But I don’t need one,” said Bruce. He smiled a bit when Tony didn’t snap back a reply. “I don’t, uh, I don’t think you can argue that.”

 _“I can argue we need you here,”_ said Tony. He didn’t bother trying to catch Bruce’s gaze with his own—it might have helped him make his point, but he couldn’t bear to lift the faceplate, not here, not standing _right next_ to Thor. _“He’s got Foster. I have to go—I can’t separate... this... from extremis—even if I stick a subspace pocket_ around _Thor somebody’s gotta drive. You’re gonna be the only guy left on Earth who understands higher-dimensional travel. SWORD’s gonna need you.”_

“He’s not wrong,” Clint agreed. He pulled out his wallet and took out a quarter, turning to Natasha. “Heads or tails?”

“Tails, and give,” said Natasha, snatching it from his hand and flipping it herself. As it came back down, she grabbed it out of the air again and slapped it against the back of her hand. It was heads.

“So you’re asking me to stay behind?” Bruce said to Tony.

_“I know, I don’t have the right.”_

“Well, no.”

Natasha leaned in toward Clint, speaking in a very low voice. Bruce probably couldn’t hear. “There’s nothing about this that will be from a distance.”

Clint’s gaze went flat, hooded again. “I know.” He turned to Bruce. “Looks like I get to keep watching your back, doc.”

“If we are not to bring anyone more with us, then we should not delay,” said Thor. He swept his hammer from his belt, a restless, unconscious motion. This time, Tony managed to keep control of himself well enough that the targeting subroutines didn’t pop up in the first place.

“Oh, no,” said Natasha, and she smiled thinly, turning to Tony with her arms held out from her sides. “I’m definitely coming along. So you’d better make me an exoskeleton.”

It was all he could do not to gape at her. By now, his frozen illusion had to look pretty damn odd. _“Are you_ serious? _”_

Clint and Bruce were watching, wary—surprised. But they trusted her. Thor looked doubtful. But Natasha smiled, walking forward until she stood right in front of him. “Dead serious. I trust you.”

 _“Hill won’t,”_ Tony fired off, scrabbling for an answer. She didn’t really want to do this. Did she? She was crazy.

_crazy, haha._

“Hill understands that Steve has command of the Avengers Initiative—and I’m his second.”

“I got third,” Clint chimed in, lifting his hand with three fingers raised.

She was crazy.

_and you are so glad she is coming along, you fucking coward._

_shut up._

To give her an exoskeleton strong enough to stand up to whatever reasonable threat they might be facing—short of being dropped immediately into a sun—he’d need more nanites than he had in the armour right now. He didn’t need to glance up to see the news helicoptors hovering overhead—there were two of them, now, both out of AED range and both sending back digital footage... streams of data he could hack, but there was nothing he could do about witnesses. He’d spotted at least two civilians with binoculars.

He expanded the range on the ICG's field to cover her as well. The power drain ticked up exponentially higher, as it always did, but the Makluan reactor could take it, and anyway, this wouldn’t be long.

_“Cover your ears. This is going to be loud.”_

Everyone but Thor obeyed—Clint, sticking his fingers in his own ears, yelled, “Heads up! Everybody cover your ears, now!”

Tony waited a moment longer to give the SHIELD agents and techs a chance to obey, and then he triggered the plates on his forearms. The noise, as always, was incredible—not just the base harmonics that made his bones hum, but other frequencies, higher than humans could hear, but which were probably the reason Thor bellowed—he was inaudible over the din—and clamped his hands over his ears in obvious pain. Sensor readings from Tony’s hands went haywire—he was sticking them right through planar flux, because he could _do_ that now—could reach in and feel around. Or, well, not feel around, exactly, because his own subspace pocket was filled with quite a lot of nanites to do the record-keeping for him... or provide him with a hefty replacement supply. He wouldn’t be caught-out like that again. He pulled them outward, feeling them flow over him until the armour had doubled its weight, and then he flicked his wrists. The gap disappeared back into nothingness.

“Your technology,” said Thor, speaking a bit too loudly, “has some far way to go.” He removed his hands, then poked gingerly at his ears.

Natasha muttered, “I’ll say.”

“What?” asked Thor, still too loud.

 _“Are you sure about this?”_ Tony asked her.

“Yeah.”

Making the nanites form into armour around _him_ was simple, pre-programmed. It didn’t really take too many tweaks to give a similar system to Natasha. This one, though, lacked most of the offensive capabilities; it was twice as thick and with defences all the way through. She didn’t have extremis as a secondary line of defence, after all.

He could monitor the heart rate and breathing of everyone around him, if he wanted to, but with her inside the armour he had to actively shut down the sensors that wanted to feed information back to him. It was just creepy otherwise. He couldn’t help but notice that she did seem calm... or was that training? He’d just closed her in a metal coffin, no sound or light—right. He uploaded a HUD, stripping most of the data from it—it had taken him days to train his eyes to use menus.

She’d need to be able to move in it. He hadn’t had to bother with haptic feedforward cues since he’d gotten extremis, but that didn’t mean he didn’t remember them all. He loaded them up, then boosted their sensitivity—she was wearing thicker armour, after all. Shock absorption he set to kick in at a much lower force than he needed; she didn’t have extremis protecting her from the inside out.

It was a crude job, customization limited to what he could do in a minute. If she had to wear it for days... well, hopefully she wouldn’t. But Loki had a twenty-nine minute lead on them.

 _“This is pretty cool,”_ said Natasha, and he had to dial back his own sensory feeds some more so that he wouldn’t be listening to her breathe. She held up her armoured hands, curling her fingers into fists and then uncurling them—not particularly smoothly compared to what Tony’s armour managed, but he controlled the armour directly. Unless it came down to a fight, _most_ people wouldn’t notice.

Natasha would, though. So it was probably good that she took a moment to test it.

“If we are ready,” said Thor. His voice was still louder than normal.

 _“I’m good_.”

“Go beat Loki’s head in for me,” said Clint with cheerful viciousness.

“I may yet try.”

Tony swallowed, shaking that away, and told him, _“Cover your ears again first.”_ Thor did, this time, along with the rest, as Tony reached into a different subspace pocket—but not quite out, not entirely. His portal device wasn’t like the massive ones he’d build before, or the one SWORD was planning to send agents through, if the Council ever got off its ass and approved a world for actual contact. This was self-transporting, for one—and it didn’t exist entirely in real-space, or in sub-space, either, for that matter. But between those two points, as he’d seen before, it was possible to hit the Void... and fall through.

It shouldn’t have been possible, according to Makluan theory. The Void wasn’t meant to be transversed at will. But the universe was falling apart, and making things that hadn’t been possible before very possible now...

 _“This will be weird,”_ he began to warn them—although only Natasha heard him, of course. She didn’t reply, not aloud. He’d have to turn the other sensor feeds back on to know if she’d raised an eyebrow.

“—after a mysterious loud noise was heard in the area. The noise now seems to be repeating—certainly an indication that _something_ is happening on the site—”

“—who was taken along with Captain Rogers has now been identified as Dr. Jane Foster, an astrophysicist currently on sabbatical from Culver and rumoured to have been under contract with SHIELD for some time—”

“This marks Thor’s first appearance on Earth since December, when he was present for the funeral of Tony Stark, the once-revered super-billionaire posthumously revealed to be responsible for the Nanoplague...” 

“All four of the remaining Avengers are now definitely on site—”

He greenlit strings of programming, and the subspace pocket inverted, wrapping around Thor and Natasha. They dropped into the Void, and all the feeds cut out at once.

 

* * *

 

Sometimes, on nights when he couldn’t put off sleep anymore, he’d close himself in a room with a cot and roll the paired Gems between his fingers, reaching through them for the certainty that lay beyond: visions of the multiverse, showing him how all these small changes could play out, convincing him keep at it rather than panic and try to do something big. Keep to the plan he’d mapped out. There were so many more snarls than he’d anticipated when he’d gone to make that request of Hel—fucking Loki, he’d had traps all over the place—and he’d had to jump around, fixing things, too often—but when he looked now, things... fell into place. He just had to keep teetering along on this highwire. He could nearly see the end.

 _Sixty years, and look, you’ve found god,_ he mocked himself.

His and Dyson’s progress was exactly what he’d predicted and still too slow for his sanity, and some days he wondered if it wasn’t that they’d been here too long, caught up in their work—that maybe he should bring in more people, but it had taken him four years to convince himself to bring in _one_ other person than himself, and another to decide on who. They drove each other crazy. He’d had to let Dyson start taking vacations more often than anticipated, getting out and about (closely monitored, of course), and hadn’t _that_ been a whole fun conversation all on its own the first time, “You see, Dorothy, you’re not exactly in Kansas anymore...” 

Or maybe insanity was making them more creative, because they were so _close._ Maddeningly close. He’d map patterns and they’d _hold_ , but it still didn’t coalesce into a whole and entire mind, an identical mind, and outside, the clock ticked down. The clock was meaningless, of course, he had all the time in the world, but still. In the world outside, people kept on dying as they had before, and he wondered what Steve would think of him now, sticking to the plan.

But then there were days like today.

“Holding...” murmured Dyson. “Alright. I’m going to try waking him up.” She flicked switches, carefully, superstitious in the way of a scientist who is paranoid that they will somehow break the apparatus before the moment of truth, no matter how protected it is. To be fair, the bio-layered silicon chips weren’t the most robust things in the world, and it had taken extremis nearly four hours to assemble this set, but the chips themselves were now locked away beneath the sheltering bulk of a roomful of monitoring equipment. Now, through that equipment and his own personal sensors, Tony saw a mind light up.

_What...?_

_Hi,_ he thought, already running diagnostics. The other began to do the same.

_I’ll be damned. It finally worked._

_Mmhmm, I’ve thought that before._

_Ha. Yeah. Check me out._

A perfect replica.

They ran tests for days more, but unlike the others this one didn’t have weird quirks fucking up the back end—no more than the original copy had, anyway. This one held together. This one was a proper mind. An identical copy.

“We did it,” Tony finally let himself say, when the tests kept coming back green after a week. A second mind spoke them in harmony with him. _“Finally.”_

“Amazing,” said Dyson, her voice hushed.

One more loose end. Eleven years working with this woman and he still somehow didn’t know her half as well as he knew—had known—Pepper. But he knew her well enough to read the triumph.

“You won’t be able to fix Eric with this,” Tony murmured, downloading a copy of it into a vial of extremis and holding it out to her. “Not directly.”

“I know,” she said, taking it with the utmost care, and turning to place it in a vacuum cradle. “But it’s so much closer.”

“Yep.” He looked back at the drive that they had created to house the other mind. He didn’t need a vial of extremis like Dyson did; his lived in him, the programs he’d used to build the bio-silicates locked firmly in his armour and his skin. He’d figured out programming a _body_ years ago—it had been one of the first things he’d done, back when he was still half-raving and trapped in the internet, newly infected, newly soulless, and miraculously alive.

“Alright, Doctor, your contract is... admirably fulfilled. Pack up your stuff, I’ve got another lab with your name on it. A bigger one. I’m sure you’ll be happy to have me out of the way after all these years.”

She gave him one of those side-long looks he’d gotten used to. The question was so familiar that he mouthed it along with her—“Why do you need a twin, Tony?”—and they both grimaced at the end. She sighed. “Tonys, now. Never mind.”

“I’ll take care of this, everything in the main lab...”

_Is it different, seeing it from your end?_

_Yeah. Maybe not how you’d think._

_Underestimating me? I’m a genius._

It was the other-him who set the lab purification protocols, arranging for the inferno to sweep through the room after Tony was gone and obliterate everything, including the newly-cloned mind himself. Tony could see him doing it, but would probably come back after anyway to make sure it had taken everything. This was a lead-lined box, and there was no way out for someone without the right Gem or a portal device to their name, but he, the other him, had one of those. Or could make one, rather. Extremis was handy like that. So he’d check, just to be certain. Maybe it was caution, maybe it was envy. Either way, he’d need to check.

The other him, reading his mind, sent over code containing feelings of deep amusement. Tony replied with a mental shrug, and they matched each other with resignation. It was risky enough, betting on Death to hide his plans; throwing Loki’s goddamned complications into the mix meant that no extra copies could be allowed to exist. The medium upon which his thoughts had been impressed had to be utterly destroyed.

He’d come too far to fuck it up now.

Twelve hours later, Tony shook hands with Dyson for the last time. “A pleasure working with you, Doctor.”

“And with you,” she said. It was a lie; he could see it all over her. Of course it was. He’d broken his word to her and she wasn’t stupid, she’d probably figured it out. So long as she didn’t try anything, it just became yet another in a very long line of regrets.

He hadn't lied to her about everything. He did need a twin. He just also needed to be able to customize certain bits of knowledge—doing so by _adding_ only, not removing—to ensure there was no gap if anyone went looking, nothing that could be restored by greater powers than him. Nothing that a cosmic force could pull out of him.

The present dissolved into blinding certainty, and Tony flung himself forwards to make a few more regrets. Dyson took a deep breath, and then pulled herself into the van Tony had procured for her. Beside her, Eric Savin sat motionless, where she’d propped him up and buckled him in.

Deep below the earth, the inferno protocols erased the last signs of their presence.


	8. Knife and Hammer: 2.1

** PART 2: KNIFE AND HAMMER **

Steve woke to the feeling of a vise tightening about his head, and nearly swallowed his tongue stifling a moan. The pain brought a rush of adrenaline, but he forced himself to lie still, to continue taking shallow breaths that did not fill his lungs anywhere near enough. His shield was still secured to his arm, and it didn’t feel like he was restrained. The floor pressing into his cheek was cool, made of stone or possibly rough tile, but the air held the tang of hot metal. A thrumming ran all through his body, carried by the floor. Was this a factory?

Behind him, muffled by a hallway corner or a partly-closed door, someone was talking in a harsh and guttural language that he couldn’t identify. That was bad; he could recognize most languages by ear. Most _Earth_ languages, that was.

He cautiously opened his eyes. Dr. Foster was sprawled a few feet away, out cold, her limbs arranged messily like she was some discarded toy—but she was breathing normally, thank God, and he couldn’t see any visible injuries. Behind her were walls lined with shelves, all filled with mechanical gewgaws whose purpose he couldn’t begin to guess at. The ceiling was low enough that even Foster, short as she was, might have to duck her head to fit beneath it.

Sitting up made his head throb even worse, and he had to hold in a gasp of pain. He curled inward, pressing his cheek against the chill metal of his shield—and the vibrations from the floor seemed to stop rattling about his brain, flowing through the shield and away. He could still feel them in the rest of his body, but the headache subsided immediately. Huh.

Silently, he climbed to his feet, staying crouched to avoid knocking his head against the ceiling. It looked like they were tucked away in a storage room of some kind. There was only one door, and it was ajar; beyond, he could hear the voices in the corridor, clearer now that the drumming in his head had faded. It still wasn’t any language he could recognize, but one of the speakers was definitely Loki.

Steve mouthed a curse. And then, as quietly as he could say it aloud, he murmured, “Thor, Heimdall, I don’t know if you can actually hear me, but if you can, Jane and I could use a hand.”

He didn’t wait to see if there would be any result. Instead he stepped over to Jane to do a better check of her vitals. Her breathing was fine, as was her pulse and skin temperature, although her face was pale. Hopefully it was just from the same kind of headache that Steve had woken up with. He eyed her and ran the situation in his head. There was no question of leaving her behind. On the other hand, should he attempt escape with her now, or wait and look for a better opportunity? If he had to fight his way past Loki... well, he’d just tried that, and it hadn’t worked so well.

On the other hand, Loki hadn’t killed either of them. Escape it was.

He’d just scooped her up over his shoulder when footsteps sounded in the hall outside, and Steve raised his shield as the door slammed open, revealing Loki standing in the doorway. Actually standing—he had _shrunk_ himself, it looked like, down to a similar height as Foster, and he’d lost his headgear.

“Please don’t tell me you’re stupid enough to be making _this_ your first escape attempt,” said Loki. He sounded tired.

Steve gave into the urge to raise eyebrow at him and said nothing. Shrunk down to five-foot-nothing, Loki looked incongruously like a teenager wearing an ill-advised Halloween costume. But Steve wasn’t stupid enough to throw the shield, either.

“You’ll have a much better opportunity shortly,” Loki added. “Come. I’ve negotiated passage for us.” He turned and walked out.

_Oh, Hell._

Outside, the person that Loki must have been speaking to stood holding a lantern—or at least, the outside looked like a wrought-iron lantern. The light inside wasn’t from a candle, but rather a glowing, floating orb. The lantern-bearer himself was a dour little man who stood a good foot shorter than Foster—or, currently, Loki—and as he raised the lantern the motion wafted the stench of sweat and ash to Steve’s nose. He had a beard that was intricately layered and braided all down his chest, right down to being tucked into his belt; compared to it, the hair on top of his head was straggly and unkempt.

Alien, definitely. Dwarf? He had human proportions, but Steve couldn’t recall if that was normal for dwarves in Norse myth. Something tickled the back of his mind—didn’t Norse myth tell of several different races of dwarves? Or maybe they were dealing with a different set of aliens altogether.

Loki gestured curtly, and the lantern-bearer turned away, leading them swiftly along the tunnel. Steve had to hunch himself to be able to follow, which made it difficult to keep up and keep his eyes peeled for opportunities. Loki had said that he’d _negotiated_ their passage, which meant that he wasn’t entirely welcome, here. That might just apply to any outsiders, but it also might give an opening.

Light shone out from a side-passage ahead. Steve made himself stay relaxed, and fell just a step further behind. He’d have to be subtle about this; he doubted he could simply charge off fast enough to prevent Loki from snaring him with more magic. But if he could lose him in a warren of tunnels, they might have a chance.

Or not. Before they reached the intersection Loki dropped back and grabbed Steve’s wrist. Steve struggled to pull his hand free, breaking the grip only with effort and the application of grappling knowledge that he was usually on the other side of. A foot shorter or not, Loki had him beat for strength. And speed—Steve dodged back, hampered by the confined space and need to protect Foster, and Loki lunged forward, one hand shoving Steve back against the wall and the other firmly over his mouth.

“No sound,” murmured Loki. His eyes were black, mesmerizing—Steve yanked his gaze away before he could fall into that trap. “I know exactly what you’re thinking, Captain, but now is not the time. If I have to bind and carry you I will, but if you run into the heart of the dhreugh fortress then they will kill you, and her, slowly. There is no way out of here without me. Do you understand?”

Furious, Steve nodded.

“Liar,” said Loki, still too quietly for anyone without superhuman hearing to catch. “A good thing, then, that there’s more than one way to chain an honest man.” His hand moved suddenly, and a cuff that Steve hadn’t seen appeared in it, with a line of chain—Steve knocked Loki’s hand aside, but Loki just tossed the cuff to his other hand and slammed it down on Foster’s wrist instead. A matching cuff, done in silver, shimmered into place about Loki’s wrist.

“Make it out of here and I give you the key,” said Loki, deadpan, and he turned away.

The chain was about eight feet long, which was just short enough to keep them tied together. Loki didn’t offer to carry Foster, and Steve sure as hell wasn’t asking. If he put Foster down, and ran, got reinforcements... but, Hell, that wasn’t an option. There was no telling what Loki would decide to do with her in the meantime.

They progressed onward through a maze of tunnels, all of them vibrating and clanging, the cacophony getting inside Steve’s head and distorting his mental map of the place. Occasionally, their dwarven guide held up a hand and motioned them all to a stop, and then they would wait, once for nearly a quarter-hour, for some unseen event to occur. Then onwards, again, always steadily downwards, always in cramped back halls. Or at least, Steve thought that they _must_ be back corridors. Nobody could actually have a world made of nothing but corridors, could they? Some of the doors he saw had to lead to rooms, and not more tunnels, surely.

They turned down yet another slopped passage, and a cool breeze from beyond brought the smell of... snow, ice—melting? It reminded him of mud and slush in European woods on a spring day. Their guide halted halfway down the tunnel, and pointed jerkily towards the end, where an unremarkable door was set into the stone.

“Ah,” breathed Loki, sounding relieved. He sauntered forward, sniffed the air, and turned to press something into their guide’s hand. Steve didn’t get the chance to see what it was before the dwarf closed his hand around it and thrust both hand and item deep into a pocket in his grimy overcoat.

“Don’t come back,” growled the dwarf. His voice sounded like ground gravel. “You try, you’ll _wish_ I had a needle and wire.”

“Always a pleasure doing business with you, Alviss,” said Loki, and he brushed by the dwarf, pulling Foster, and therefore Steve, along with him.

Behind them, their guide grunted and extinguished his lantern, plunging the corridor into sudden, total darkness. Steve breathed deeply and pushed away the unexpected claustrophobia. Tunnels. Why did it always have to be underground secret fortresses—

Ahead, Loki snapped his fingers and a flower of green light bloomed into existence above his hand, its petals falling outward and casting patterns up at the walls and ceiling. Steve risked stumbling over his own feet and took a glance backward. Their guide was gone. He’d made no sound while leaving.

Loki examined the door, tugged on the lock, and then gestured at it.

Nothing happened.

“Sure you can trust your friend?” Steve asked him.

“Hardly a friend.” Another gesture produced a set of lock-picks. Loki fit them into the lock and had the door open a few seconds later; he dropped the picks carelessly, and they melted into light before they could hit the ground. The door opening let in a rush of air, the smell of snow now mixed with mildew and the beginning of damp rot. Steve breathed in, and followed Loki through into the darkness.

Beyond lay a cavern—an _enormous_ cavern. Steve straightened up immediately, the muscles in his neck and upper back burning with relief, and took a good look around. He could feel more than see the vast open space of it. Loki’s flower illuminated a few enormous, impossibly thin stalactites, water droplets clinging to their tips, but the walls and roof of the cave were beyond its reach. In here, the tremble of distant machinery was much less, as though they were somehow insulated.

Behind them, the door began to swing shut, and Steve paused long enough to slow it and ensure it closed quietly, which earned him an approving nod from Loki. Loki, who... was somehow now taller than Steve, again, although Steve hadn’t seen it happen and would have sworn he’d not looked away.

“I believe we can now dispense with this,” said Loki, tugging at the chain near his wrist. The cuffs on either end of the chain fell open, releasing Foster as well, and Loki coiled it up and made it vanish. He gave Steve an examining look, his eyes turned green by the reflection of the fire-flower he was holding.

_Wait, no—_

Too late: he’d looked at Loki’s eyes directly, and the reflection there wrapped around him, green haze flooding his thoughts—

 _Oh, no, you don’t._ This wasn’t the first time Steve had fought something like this. His shield was more than just a weapon: it was defence, _his_ defence, inside and out, and when he reached for it, it was there in his mind's eye, impossibly large and solid, a shield, a fortress, a _bastion_. Everything he’d fought for in gaining the right to wield it, everything he’d fought for with it—the shield gave ideals _form_ , and ideals were stronger than vibranium. Loki’s power crashed against it and was repelled.

Steve blinked and was looking at Loki again, firmly in the physical world once more. The shield remained at the forefront of his mind. Loki looked taken aback, as caught off-guard as he had been—the other him—when Natasha had duped him in the Helicarrier’s glass cage.

“You’ll have to do better than that,” Steve told him.

Loki grimaced. “Ah. That’s for the best; ensorcelling you would be... counter-productive to the current goal. Forgive my lapse in self-control, Captain.” He bowed, low and from the waist, a courtly gesture than was either mocking or Asgardian. Steve couldn’t tell. When he rose, his lips were fixed in a thin smile. “I’m afraid I cannot promise it will not happen again. My mind tends to... wander, since my fall through the Ginnungagap. Be on your guard.”

There was a shift in Foster’s breathing. Steve spent a moment debating putting her down—if he had to run, she wouldn’t be able to keep up on her own two feet—and then shifted her gently off of his shoulder, cradling her instead. They weren’t going anywhere with Loki watching them like a hawk. “What do you want, Loki?”

“Hmm. Stark didn’t tell you anything, did he?”

“He told me you wanted his help. I can see why he refused.”

Foster stirred, her eyes fluttering open, and groaned. Steve lifted his hand to block her sightline to Loki.

“He was a bit dramatic about it,” Loki complained.

Steve managed to avoid rolling his eyes by dint of reminding himself that they were in the exact opposite situation they’d been in on the Helicarrier, and that had been a less powerful Loki. “Dr. Foster? How are you feeling?”

“Mnngh,” grunted Foster. Then, “Ow, my head—Darcy!” She fought her way upright, and Steve let her down onto her own feet, keeping a steadying grip on her shoulder and stepping between her and Loki. “You—St—I mean, Captain, she needs—oh my god, where are we?”

“One of the hidden places in the world,” drawled Loki.

“Oh my god,” said Foster, trying to peek around Steve.

Steve dodged so she couldn’t and held up a hand. “Dr. Foster, don’t look at his face—he can read your mind if you do, maybe more.”

She glared at him, instead. “Why are you just standing there? He, he attacked us, he attacked Darcy, she might be dead!”

 _Damn it_. He’d hoped that Loki hadn’t bothered going after Lewis, once he’d blown Steve through a wall and grabbed Foster. He turned back, standing halfway between both of them.

“I merely reflected her own attack,” said Loki. He managed to sound harassed. “She drew a weapon first—if she didn’t know how to properly avoid it then she shouldn’t have tried to use it.”

Foster made an attempt to dodge past Steve and Steve caught her, holding her back—Foster’s expression was like a thundercloud, hurt overridden by anger. “Let go of me!”

“Dr. Foster! Calm. Down. _Think.”_

“He murdered Darcy!”

“Tasers are supposed to be non-lethal weapons!” Loki half-shouted, and threw up his hands.

“Don’t give me that BS, you sicko freak—”

“I am _sorry_ if I hurt your friend, but given she _attacked_ me, I don’t think it was really my fault.”

“Oh, please, like she was actually a _threat_ to you—”

“Both of you, ENOUGH!” barked Steve, pitching his voice like a drill sergeant. Jane blinked and shut up, looking betrayed; Loki turned on him with a blistering stare. Steve chopped his hand down in a sharp motion to cut off his protest—an _explanation_ was what was needed right now. “Loki. What the hell do you want?”

Foster opened her mouth, but Steve cut her off with the same type of glare, and waited.

“If Stark had actually explained anything to you, this would be so much easier,” Loki grumbled. Then he looked thoughtful. “Or perhaps he simply took my warnings past the bounds of rationality... which may not be so far past.”

“Loki,” growled Steve.

“I need your help,” said Loki. “To save this multiverse.” He glanced between them. “I thought perhaps _your_ help would be sufficient, Captain, but seeing you as well, Dr. Foster—you may be the one needed instead.”

“I am not helping you, you—you _maniac!_ You tried to kill Thor, and—”

“That actually wasn’t me.”

“No, from what Tony said, _you_ succeeded in killing Thor. _Your_ Thor,” Steve cut in. “Where are we?”

“Far from any place that he might be able to hear us—you can shout the Thunderer’s name until Thanos arrives, he will not hear you.” Loki bared his teeth. “Did Stark mention how Thor helped tie me to a rock so that I could be kept in tormented agony for an age? No? Then you can kindly _hold your tongue._ I am trying to save your lives and all the lives in this miserable wreck of a universe, you might show some _gratitude_.”

“Oh, shut up,” said Foster in disgust, crossing her arms. Steve noted with relief that she’d at least taken Steve’s advice about looking Loki in the face, and was glaring at his shoulder instead.

“Attacking us and seriously hurting our friends is not a good way to ask for help,” Steve told him.

“Well, I had to make it look good,” said Loki. “Stark truly told you nothing, didn’t he? Hmm. I’m being watched, Captain, _very_ closely watched. All whom I come into contact with are suspect... but my ‘enemies’ less so.” He spread his hands, wide and empty, which wasn't at all a reassuring sight, not considering how many things Steve had seen him pull from thin air in the last fifteen minutes. “With him it was possible for me to pass along a... more coded message, you might say. Whether or not he’s chosen to _act_ on it...” He huffed out an aggrieved breath.

It was entirely possible— _likely_ , really—that Loki was lying. Sure, SHIELD’s scientists agreed—more or less, now that there was debate over Tony and Bruce’s paradox—that Thanos was still around. That didn’t make him not a liar in general. There was one thing that Steve didn’t doubt, and that was that Loki terrified Tony. But that wasn’t something he could think about, not here, not this close, not when he didn’t know how powerful a telepath Loki really was.

“If it’s so dangerous to be telling anyone anything, why say it now?” asked Foster.

“As I said, this is one of the hidden places of the worlds.” Loki gestured around them. “The dhreugh’s Grand Device causes enough noise to hide the entrance, and the place itself does the rest. _Here,_ we can speak freely, and even Thanos cannot hear us—a precaution granted almost nowhere else.” He paused. “Although your little device was very impressive. I’ll have to take a closer look to determine if it will truly fool the Titan himself, however.”

“You do that,” said Foster bitterly.

“Hey,” said Steve. “Did you take it?”

“Well, yes.”

“Then give it back to the lady,” Steve ordered. “For God’s sake, if you need our help you’re going to treat us as equals.”

Loki narrowed his eyes. Steve forced himself to keep breathing evenly. This was a kind of test, and he’d failed terribly at it with Tripitaka... but the corners of Loki’s eyes crinkled upward in silent laughter; he made a gesture and Foster’s device appeared in his hand. He threw it to her, and she fumbled to catch it, hugging it close against her.

“You k—you hurt Darcy. I’m not just going to forgive you that!”

“Peace. I am not asking for you forgiveness, only truce. An alliance... a temporary one, if you must insist, but the fact of the matter is that you _do_ need my help. Thanos is regrouping from the blow the Living Tribunal dealt him, and the pantheons will fare no better against him this time than they did before. You need my help, and for me to help you, I need yours. What say you?”

Steve glanced at Foster. She was glaring at a nearby stalactite. Fair enough. “What exactly do you want from us?”

“I have a plan to defeat the Titan. There are... objects in this multiverse, this _set_ of multiverses, that are more powerful than that within which they are contained. They’re tricky to use, trickier to find. I asked Stark for his assistance in obtaining one such—but if he’s not told you about that, then I suppose he’s refused entirely.” Loki looked irked by this.

“And so you took us, what, as motivation?”

Loki grinned. “Only a bit. I’ve found where another is, and this one is easier to reach... for a paragon. An _idealist._ ” His grin turned mirthless and his eyes were shadowed. “We gods are what we are made to be; for this I need the assistance of a mortal. And who is more of a paragon of humanity than Captain America?” He paused, and nodded at Foster. “Though you may also qualify, Lady Foster. I have seen your devotion to your work.”

“Go to hell,” said Foster. She was shaking slightly. The initial adrenaline rush was fading; fear was probably creeping in. She was a civilian, and Loki had just killed or at least seriously injured her friend.

“If these things are so powerful you can’t think we’d let you have it.”

“I don’t, actually,” said Loki. “Although this one is not _that_ powerful all on its own. No, I would be content with putting these gems into the hands of someone who only wants to destroy Thanos—idealists can be counted on to be rather _reliable_ about this. Well, the proper sort of idealist. I wouldn’t want Stark to have one. Perhaps... yourself, Captain?”

“If that’s a bribe, I’m not taking it,” said Steve firmly. Gems. Like the soul gem? Steve filed that away in the back of his mind. “What is this thing and where is it?”

“This,” said Loki, holding out a hand. Green light crystallized above it, and turned blue—a near-exact image of the Soul Gem, chromatically shifted. “It’s called the Stone of Thought, or the Mind Gem... and for eons it has been hidden here.” A second image bloomed into being beside the Gem: Two pillars, standing atop a pile of rocks. The pillars were little more than rocks themselves, whatever features they may have had eroded away. “The Temple of Uttermost Wind.”

Steve hesitated. “You’re not the only one who’s thought of this. The Chief Magistrate of the Infinite Embassy already considered them. They can’t defeat Thanos.”

Loki looked thrown for only an instant. “You’re even more remarkable than I thought, Captain Rogers. There are not many mortals who can claim to have walked the halls of the Infinite Embassy.”

“What’s the Infinite Embassy?” asked Foster.

“Neutral territory. Or so it once was. With the Tribunal destroyed, I imagine that if Thanos is cast from this universe, the Embassy will be the first casualty. We gods do like our wars. But tell me, Captain, how _did_ you earn entrance to it?”

“I was a guest of a Sorcerer Supreme.”

‘ _Sorcerer supreme?’_ mouthed Foster.

“Lie,” drawled Loki. “No... how did you come to be considering the Infinity Gems with the Chief Magistrate?” His eyes narrowed. “You _had_ one.”

 _Threat_ crackled in the air; Steve reached out and pushed Foster behind him, raising his shield both mentally and physically. “ _If_ I did, I don’t anymore!”

“Hmph.” Loki waved a hand; the images of the Mind Gem and the Temple disappeared, and so did the sense of imminent attack. “Lost it, did you? Or perhaps you gave it up? It doesn’t actually matter. Each Gem has a mirror in every reality, a minor gem, so to speak.” His precise diction made it easy to hear the difference in emphasis, like audible capitals. “You must have had one of those, if a Sorcerer Supreme gave it to you. If you’d had one of the _real_ things, a full and proper Infinity Gem, I would know. But the mirror gems can’t be used to locate the true Gems, sadly—and they are only mirrors. Limited, cheap copies. Trinkets, compared to the true thing, although I suppose a mortal would consider their powers worthy of respect.”

Steve had looked into souls with that gem. He’d seen the truth of Stephen Strange and Anthony Edward Stark; he’d seen Hercules and the impossible _other_ that was Amora. And that was _limited_?

Loki absolutely could not be permitted to get his hands on the Mind Gem—or even just _a_ mind gem.

“How many of these Gems are there?” asked Foster. “What do they do?”

“Six of them, in a set,” said Loki, still staring hard at Steve. “Each Gem’s powers differ, according to their nature. Which did you have a mirror of, Captain?”

“Which Gem did you sent Stark after?” Steve countered.

“The Stone of Time.” Loki looked away, vexed. “Assuming that I am correct in its location; I have been chasing its mirrors for... well, some _time_ now.”

“Why are _you_ doing this?” Foster demanded. “Stark said you were from another cluster. Why do you want so badly to save this one?”

“What, Stark told you that, and didn’t describe the sheer amount of effort it took for me to disentangle myself from that one? Asgardians are not mortals, Lady Foster. You may travel between two places simply by conveying yourself in a suitable fashion. _I_ had to uproot myself from the very weave of destiny. Although I wonder at the jokes of the Norns, that I find myself here instead.” Loki scowled. “The span of time before Thanos destroys us all grows short, and I cannot repeat that feat so swiftly. Ergo, I must see this _cluster_ , as you describe it, saved. If I must track down every Infinity Stone myself and see it into the hands of an _idealist_ to do so, then that is what shall be done.”

That was certainly a self-centered excuse to do the right thing. Perhaps it was just a bit _too_ convenient? Loki couldn’t be trusted, even if he put things in terms of his own self-interest. And while the White Tiger had said that Loki was on their side in this fight, Steve wasn’t terribly certain that the White Tiger was much better; after all, the cat had been helping Kuan-yin, and... he couldn’t think about what she had done.

“And if we refuse?”

Loki smiled. “I would drop you back off with your friends, of course, and find myself another paragon.”

Right.

Steve glanced down at Foster. It _was_ down; she was a tiny woman. Even before the serum he’d have been taller than her. She was a civilian, untrained, unused to even the back-alley fighting that Steve had grown up with. On the other hand, she was also Earth’s foremost scientist in interdimensional travel, or would have been if Tony hadn’t cheated and downloaded an alien database into his brain. “Dr. Foster. Thoughts?”

“He can’t be trusted,” she said mulishly, clutching at her silencing device. Then she sighed. “Like we don’t all know that.”

Steve lowered his voice. “Can you do this?”

She got a pinched, indignant look on her face, and Steve concealed his own wince. How many times had he heard variations on that question? _Dumb, Rogers. Dumb._

“What I want to know,” she said, very precisely, speaking to Loki now, “is how exactly you bridged us out of there. You didn’t have Bifrost or anything like it—you’re using something different.”

“Oh, is that your price?”

“Yes.”

“Easily paid, then. You could call it mirror walking, I suppose. It’s not something a mortal can perform.” He smiled. Steve really wished he’d stop smiling so much. “We Asgardians are scattered across the limbs of the Great Tree, but unlike you we are connected... and those of us who know how can always reflect back to ourselves. I had to cast protections on you so you wouldn’t be damaged by the passage when I took you with me, but even then, you were a bit bounced around, hmm?”

“Mirroring,” said Foster, sounding it out. “...Quantum mirroring? You’ve got... you’re interlinked, all of you.” She had an expression on her face that Steve recognized from working with far too many scientists—not quite the ‘aha’ expression, but worse than that: the _almost_ -‘aha’ expression, the peak of curiosity. “Oh... _oh!_ ”

From a pocket, she pulled a little flip-notebook and pen, and began scribbling.

Loki gave her a glance that was not quite an eye-roll.

“You’re still a murderous asshole who hurt my friend,” said Foster without looking up.

Loki waved this off. “That is the consequences of playing with gods, mortal. May I see your... device, once again?”

Foster glanced up—an instinctive reaction, to try to look someone in the eyes to judge their intent. Steve stepped between them and she swallowed. “I— _why_?”

“Does it matter?” Loki asked. He sounded genuinely curious. Just as genuine as he’d sounded through most of this conversation. Steve scowled at him. “I am _asking_ ; I should think that sufficient. Do you really think that if I had a mind to, I couldn’t have you simply hand it over to me?”

Foster transferred her gaze to Steve, question lingering in her eyes. Then she frowned, looking at the device.

“You’ve got blueprints back on Earth, right?” Steve asked.

“Yeah, but, if I just _hand it over_ —” she said, mimicking Loki’s words with a mixture of fear and frustration, and shook her head. Some of her hair fell into her face and she brushed it away angrily. “ _Argh._ Why?”

“It _would_ be more convenient if we could leave this place, and proceed to the Temple, without need to then curtail our own conversation,” said Loki dryly. “I didn’t have enough opportunity before to examine it, but it may hold the answer to that problem.”

“Yeah, amazing what us mortals can do,” Foster muttered. Then, reluctantly, she held it out—to Steve. “Fine.”

Steve frowned. “You sure?” It was, after all, her work... and probably the most advanced piece of tech they had with them right now. If she and Steve needed to use it later to make a plan to get around Loki, then letting him have a look at it was a terrible idea. On the other hand, he had a point about asking... because he’d known what she’d say? Or because he’d ‘convinced’ her?

 _Argh._ And now he knew why Foster had felt like that. Just as reluctant as she had been, Steve handed Loki the device.

“Thank you,” Loki murmured. He levitated it upward with his magic, the air around the device clouding to a haze of green. “It does resonate with this place...” He tapped the case, and it split apart into two halves, which hung in midair on either side of the internals.

Then he did it _again_ , splitting apart the components, and Foster surged forward. “Hey!”

“Do you even know what you did, in creating this?”

“No, I threw together a space-displacing cloak-anti-cloak for sound waves by accident.” Foster glared. “Of course I know what I did, you prick!”

“Well, then.” Loki brought his hands together, a motion that was uncomfortably familiar to Steve—Tony moved his hands just so, when he was re-sizing holographic schematics. “A crude approach, and jumbled, but it will suffice for now.” The device dropped into his hand, and he proffered it to Foster.

“It’s a hand-built prototype, it’s supposed to be crude,” Foster grit out, snatching the device from him and stepping back behind Steve.

“Art is never supposed to be crude.”

There was immediately an objection on the tip of Steve’s tongue. He swallowed it down before he could get drawn into the derailment. “Are we going, then?”

“Yes, directly.” Loki's eyes were lit with anticipation as he turned a sly smile on them both. “You may wish to brace yourselves. From your previous reactions, I’m given to understand this is disturbing for mortals.”

Foster shrunk in on herself, a miserable, determined huddle. Steve just forced himself not to tense up. Bracing yourself against a roller coaster was the worst thing you could do. Loki’s grin grew wider—wider— _too wide_ , thought Steve, and—there was green around them, everywhere, pulling him out of his body and out of his mind. He might have shouted, might have screamed—a wordless howl of protest. He couldn’t hear himself. He _could_ hear screaming.

Mercifully, just before his mind really _did_ detach, everything went black.

 

* * *

 

Fire roared against the armour, crisping the outermost edges. The more sensitive sensory modules, the ones sitting on top instead of underneath the denser protective layering, fried immediately.

Temperature: 684

_yeah this was a terrible idea_

_run seeker.exe_

The air shimmered with heat, bending and distorting both light and his sensor readings. Beside him Natasha's armoured pinged continually against the back of his brain, letting him know it had temporarily slaved to his position and velocity. That was the autopilot, which had engaged as soon as they’d come out someplace without a solid surface to stand upon. He hoped she wasn’t freaking out at that. He could re-engage the internal sensors—no.

Thor, hovering in place with his hammer humming over his head, had flames dancing down his cape. Aside from the sweat dripping from his brow and bare arms, he appeared to be fine. “Tony, Natasha! We cannot stay here long.”

_understatement_

They had appeared more or less directly over a molten river of lava. It was their damn good luck that they _had_ been so far from the surface, actually—extremis wasn’t lava-proof, even in the armour’s configuration. _have to fix that later_ It wasn’t a nice, well-contained river, either: it was wide with a meandering flow, from which the occasional strip of black obsidian poked out. Longer-range sensors showed only more of the same. Occasionally, larger chunks of cooler rock indicated some solid land-mass, but for the most part it was lava, lava everywhere. Atmospheric and particle analysis noted that the poisonous gasses were through the roof. He pared the basic feed down and shunted some of it to Natasha with a thought; maybe she’d find it useful.

“ _Thank you for the suit,”_ she said, on internal comms. Quick study, if she’d figured out how to switch those already. He further lowered the amount of eavesdropping he was doing. On speakers, she asked, _“Is he here?”_

Target: not found

“ _No. Fire it up, Thor.”_

Thor retrieved the locator and held it out with his free hand, concentration writ across his face—and then he paused, glancing downward doubtfully. Of course; lava seventy-one metres below them made a poor surface to read off. Tony dropped down and closer, ignoring the way it made his stomach swoop for reasons that had nothing to do with the actual movement, and put his hand out directly under the gem. Thor nodded, and it started to spin, tracing circles of runes along Tony’s palm. Not fast enough for his tastes... he willed it to go faster. Loki had jumped once; how many times would he jump again?

“ _Can you use that thing to find him if he doesn’t portal out directly?”_ asked Natasha.

“Howso do you mean, ‘directly’?”

“ _If he flies off a mile before he portals,”_ she clarified. _“What’s the range on it?”_

“It does not track only portals.” Thor shook his head. “No matter how he runs, we will find him.”

“ _Only if we can catch up fast enough,”_ Tony put in. _“Tell me how it works.”_

“I cannot teach you to use it, Tony. It is bound to the royal line.”

“ _It’s too slow, is what it is. There has to be a way to improve it.”_

“ _He’ll have to stop sometime,”_ said Natasha.

But Loki already had a lead. Security camera footage had showed how fast he could bridge to another world, and it was just slightly faster than Tony could manage to drag them through the Gap. Loki’s was clearly a different method than the Makluans used. He would have wondered how it worked, except that wondering how Thor’s tracker worked was more important.

“ _Is the speed of this a function of the display or does it take this much time to actually track him?”_

Thor shook his head. “I don't know. I can use it, but I’m no sorcerer, Tony.”

_damn it_

Could he try and take it apart? That might cost them more time than it would save. He bent all of his sensors on it—not a great solution, with the more delicate ones having been singed away—and continued the readings he’d begun back on Earth. The armours’ temperature gradients crept upward in the back of his mind, but they’d be gone before that became a problem...

The coordinates finished, looping back to the start. _“Got it,_ ” said Tony, and yanked them all away.

The world they appeared in this time was remarkably pleasant, by contrast. Armour repair set to with a will. Below them sprawled a woodland area, pleasantly seeded with flora and fauna that were far from Earth-based but not coming up toxic on analysis, either. There was a gleaming golden city off in the distance, nothing so grand as Asgard, but nothing to sneeze at, either. This world was inhabited. Then again, the last one might have been, too.

“ _Go,”_ he told Thor, firing up his own seeking program. Just because his program was faster didn’t mean they couldn’t run them simultaneously, and Thor’s had better range. They should have worked simultaneously from the start.

His came up empty. They waited for Thor's coordinates to finish, and jumped.

Past the Gap—another world. This one was stranger; plants like strings of coloured taffy strung upward from the ground and drooped over each other. The atmosphere was seventy percent helium. _“Can you breathe this?”_

“Not for long,” said Thor, his voice like a chipmunk.

Natasha made a noise that wasn’t quite a laugh. _“You’ve experimented with helium before?”_ She was still getting the pared-down atmospheric reports.

Thor scowled at her, and squeaked, “It’s a common enough past-time for children of most worlds with access to such.”

“ _I wasn’t judging.”_

The next world held wind-blasted plains, and a rad counter high enough that Thor would need to decontam later... unless he didn’t have to worry about such things. He didn’t seem worried when Tony told him. “I don’t fear the ghosts of past weapons.”

“ _Is that a trait common to Asgardians?”_ Tony asked him.

“We are no more all alike than you are all alike, Tony.”

_damn it_

Jump, and they were underwater. This, for the first time, made Thor’s eyes widen, but he held his breath, and Tony could see his heartbeat slow: a survivalist’s response, not just a warrior’s. _“How long can you hold your breath?”_ Tony asked.

On his free hand, Thor flashed all his fingers thrice.

“ _Does that mean the same thing in Norse?”_ Tony asked, and earned himself a look that was probably the Norse equivalent of an eye-roll.

Another world, and another. Loki had at least an hour’s lead on them now, if he hadn’t paused along the way. “He is not making this easy on us,” Thor said grimly. “These worlds—I’ve heard of them only in passing, and never before set foot upon them myself. They are obscure indeed.”

“ _He knows you can track him,”_ said Natasha. _“This is way beyond ordinary precaution. He knows he’s being hunted.”_

Another world, one where cities floated in the sky. Tony gave their tech a cursory scan while Thor’s tracker whirled. The next world was barren of life, with a 99.99% N2 atmosphere, and at the one after ships were assembled in military formation; a pair of scout-craft broke off to interrogate them, and Thor had to conduct a negotiation-by-Allspeech as the tracker whirled. Apparently, the Prince of Asgard wasn’t yet known as an exile, because the scouts stood down at his word. Another world, and they stood on a plain of ash. Particle analysis said it was bone.

Anoth—

Feedback screamed over his brain. Tony wrapped Thor and Natasha deeper in subspace and inverted his equations, slingshotting them backward. Some part of him was distant, shaking, as they re-emerged over the bone-ash plain. That had been close. That had been _power_. He was reminded of Loki’s smile with too many teeth. Or perhaps it was _this_ world, and the memory of ash as Asgard burned...

“Tony?”

“ _Tony, what happened?”_

“Shields,” he managed. “Uh. Wards.” The disadvantage of using this method of travel, rather than the portals he’d previously cooked up. Portals just refused to open. Or, in Maklu’s case, dumped you... elsewhere. This one—this had been different. Was it just that the wards were different? But the sickening sense of wrongness...

“No,” said Thor. “That was... that was strange, indeed.” He’d lifted the tracker again, letting it spin. Tony recorded the details automatically, although he didn’t need to: the way forward hadn’t changed. Thor looked frustrated. “It has been a long time since I learned the passage-ways, and longer still since I learned how to calculate them. And we have made many jumps. Tony, do you know where we are in relation to Earth?”

“ _Sure.”_ Sort of. He’d taken them here, and he could take them back the same way—but collapsing that down, simplifying it into a single jump... he wished he had his backup extremis bank here. He could pull the other backup out of subspace, true, but... no, best leave that one where it was, it had other things to do. He left it alone and started on the problem with the processing power he had readily available.

Their location relative to Earth shouldn't matter, anyway, because Earth had nothing to do with the problem. Even the current world had nothing to do with it: it was solely on the destination-side. He wasn’t going to be able to work his way through wards like that in a hurry. Loki’s lead had just jumped to days, minimum. Unless Thor knew another way...

“ _We're here,”_ he said eventually, formulating it into the same circular patterns that the tracker used and projecting it onto the ash at their feet. It made for a good surface, flat and perfectly undisturbed except by their own footprints—which was strange, since this place _did_ have an atmosphere. Loki’s footprints were nowhere to be seen, which meant he was probably flying, somehow. Hopefully he was still carrying both Steve and Foster. _“And the next place is... here.”_

Thor blinked, taken aback. “I hadn't realized we'd travelled so far. I have never crossed to the Elseworlds before.”

Damn. And, possibly, _damn,_ if that meant this aspect of his didn't have direct experience with alternate realities; could Tony trust what he'd said about keeping promises? _no, don't think about it he's fine for now he didn't even notice the change—_

There might be another way. _“Hang on.”_ Tony reduced the dimensions involved, which took more creativity than he'd been expecting, and then projected another set of coordinates. _“This is its location relative to this reality's Earth, if it's in the same spot ours is in back home.”_

“...Ah.”

“ _Ah?”_ asked Natasha.

Thor looked grave. “If your assumption holds true, then the next realm is Hel.”

_of course it is_

...did she know? This one?

What _did_ she know?

“ _Then... not wards.”_ Tony considered. _“The living can’t pass.”_ _especially not me_ _“Except maybe by the proper bridges.”_

“The Gjallerbru, yes.”

He’d walked across the Gjallerbru before, and watched an entirely different Steve vanish before his eyes. Great. Was there another way in? _“Will Modgud let us pass?”_ He gestured to Thor. _“You said you were persona-non-grata.”_

“ _How did_ he _get into Hel, if the living can’t?”_ Natasha interjected.

Tony gestured to Thor to explain that one. He was devoting more of his own processing power to calculating the direct route to Svartalfheim—or where he'd hoped it would be.

“He may have knowledge of a forbidden route. Or... he is Hel’s father. It may be that he has suborned her to his cause.”

“ _Don’t write her off that quick,”_ Tony muttered. _“She knows what a piece of crap he is.”_

Of every being in that other Asgard—Odin, Frigg, and Thor all among them—Hel had been the only one to _act_. The only one to try to stop Loki. The only one to see the future to come... did this one know, too?

Could it be that simple? They weren’t in the nexus, here, the core of worlds. But he’d _fallen_ in once before—gone the direct route. Was that all that was required?

“Hel,” Tony whispered, breathing into the silence of his helmet. “Lady Hel, God of the Dead. Please let me in.”

A crow squalled, long and garishly loud in the still air. Natasha jumped high enough that the armour stabilizers caught her on the way back down; Thor vanished the tracker and raised his hammer. Tony looked, with every scanner at his disposal, and there wasn’t a crow anywhere. There wasn’t anything else different from before, either.

“ _Trying this again,”_ he warned them, and activated the bridge.

Again they hit the same resistance—it bent subspace back against them, the Gap drawing dangerously near. Tony turned the inducers up to max and held them all suspended, the whine of power draw from the Makluan reactor ratcheting upward exponentially. Even it couldn’t keep this up long. But that barrier—it wasn’t quite a barrier. It was the absence of barriers... the absence of their own barrier. With that down Natasha and Thor would be stripped raw, laid bare before the Void—just as he already was, but he didn’t have a soul, did he?

Was that all it took, to come physically to the realm of the dead?

“ _Tony!”_ Natasha shouted. Thor might have been shouting something. Their cocoon was unravelling, and with it, sound and space. Very shortly there would be no barrier.

He could send them back...

...leave them stranded.

Send them back to Earth, then...

No. Hel might or might not tell him what he needed to know, and in the latter case he'd need Thor to keep tracking Loki. And Natasha... if he was taking Thor, then yes, he wanted Natasha there.

_huh_

It was a surprising thought.

Right. Then— _“Sorry, really sorry, you can’t see this,”_ he told Natasha in a rush, and the armour squeezed inward on her carotid arteries. She went limp. _“Thor, close your eyes.”_ It wouldn’t do any good. Well, a glance hadn’t... permanently damaged Tony. That had taken much more than a glance. A glance might... _hmm_

Warnings lit up. The reactor had plenty of _energy_ left, but it couldn’t keep up this level of power output without damage. Time to go. He dropped the side of the barrier and grabbed hold of them with his bare gauntlets.

Makluan technology hurtled them forward. Asgardian technology—or maybe that _was_ the wrong word after all—ripped subspace free from around them. They fell through into the Ginnungagap, a black space filled with not-stars. Thor’s eyes went wide with horror. There was no air here, but from what Tony recalled, that wouldn’t make a difference. That wasn’t what Thor was horrified about, anyway, if Tony made his guess. He followed the direction of Thor’s gaze, but there was nothing there. Could he not even see the roots of Yggdrasil anymore, without his soul?

They fell, faster, as fast as Tony could push the boundaries of physics, but time stretched out as he watched Thor’s expression, horror beginning to comingle with despair. Memory crashed down on him—the memory of how time seemed to stop, standing still in that moment of _impossibility_. But _his_ memories had been recorded onto Makluan nanites, the ones that Tripitaka had forced him to use upon his own past self, closing the loop... they were soulless memories, and they didn’t show whatever the thing was that had so horrified him.

‘ _No,’_ Thor mouthed.

Tony could only see stars. What _were_ the stars, in this place? Merely other worlds? Or whole other multiverses? Clusters themselves? He could do the math to travel around here, but behind these walls, in the underbelly of reality, how the mind chose to interpret it was something that he would never understand.

They hit their coordinates, and Tony pulled them through reversion, and out onto the dull grey plain that he’d seen in his nightmares for months.

Thor fell to his knees, his hammer dropping from his fingers. He had his eyes closed—the look of a man struggling to pull himself back together. Beside Tony, Natasha woke from her brief foray into unconsciousness and took two quick steps back; he ceded back control of her armour before she could feel any extra resistance from it. She kept her voice remarkably even. _“Tony, what the hell was that?”_

“ _We had to go straight through the Gap. The Ginnungagap. You, uh. Don’t want to be awake for that.”_

“ _I’m not sure it made a difference.”_ There was an almost undetectable vibrato in her voice.

“ _Sorry.”_ What else could he say?

Natasha switched to internal comms. _“Don’t do it again.”_

“ _What about on the way out?”_

“ _You let me make that call, Tony. You don’t make it for me.”_

There wasn’t time—no, he could have asked beforehand. _“Fine.”_ Moving on. Sensors didn’t penetrate the grey much better than human eyes had, but he couldn’t detect Hel in their immediate range. Hel, or anyone else. _“Thor, get up. We need to keep going.”_

“I—” Thor shook his head, his hair falling about his face. “Yes, of course.” He put one hand on top of Mjolnir’s handle to lever himself upward from kneeling, but didn’t pick it up as he stood. In his hand, the tracker began to spin almost listlessly. His attention wasn’t focused on it, but rather on their surroundings.

“ _What is it?”_ Natasha asked.

“I... that was not a method of travel I had... considered.” He shook his head. “Nor one I will take again, after we leave this place. But if we are _here_... I have not seen my niece in an age. I would wish...” he trailed off, wistfully.

“You only ever had to ask, Uncle,” said a voice like an old crone’s.

The tracker stopped spinning as they all turned in unison. For an instant Tony thought that Thor had lost his concentration, but then Thor glanced down at it, frowning and puzzled. The tracker remained unnaturally still.

“Why do you hide his trail, Hel?” Thor asked, raising the tracker higher.

“He requested it of me, and paid a suitable price.” Her gaze cut to Tony. “Have you come to bargain with me again?”

“ _What is she talking about?”_ Natasha demanded over the internal comm.

“ _I—she’s lying,”_ he replied. It sounded weak, like a lie, but beneath that dead gaze he couldn’t manage force. That Hel had been a cluster away, and even Asgardians were limited to their own cluster. Loki’s attempt to flee his was the whole damn problem. On external speakers, he tried, _“You were lying—you—how do you even—?”_

“Death. Eternity. Infinity. Inevitability,” Hel hissed, extruding satisfaction at the sound of each word. “You mistake me, _mortal_.”

“ _Air here’s breathable,”_ muttered Natasha. _“If I say I want out of here, you let me out. I can’t fight like this.”_

“ _There is absolutely no point in fighting her.”_

“Enough,” said Thor, raising the device once more. He sounded weary. “Yes, they are mortal, and they are under my protection. This device is of the royal house, niece, and you’ve a lesser claim than I. If I must break the hold your will has upon it, it will not go well for you.”

“You may be first in line to the throne of Asgard, Prince Thor, but here I am _Queen_.” Hel stood, pushing off of the skulls that formed her armrests, and somehow gained half a metre in height in the motion. “This is a pointless conversation, when you so limit yourself; it is as talking to a doll. _Come!_ ”

The world around them changed. It was difficult to say exactly how. The transition was smooth, flawless, and as quick as it had been in Maklu when time had been falling into pieces around them. Tony’s sensors pinged back the realm of the dead one moment, and again the realm of the dead the next, but there was something _off_ about the data. He switched focus to the suite he’d used to track distance and time in Maklu— _bingo._

Thor stood tall, and although nothing in his appearance had changed, there was absolutely no doubt that he was now _more_ than he had been. The sum of all parts. He cast his gaze at Natasha and Tony, concern written in his expression, but he was... this was _Thor_. Not to be trusted.

Mjolnir in hand.

“ _Shit. Shit. Natasha—he—”_

“ _Calm,”_ she ordered him. _“Tony, breathe. If there’s no point fighting—then that’s what I do best, remember?”_

Right. Taking the fighting out— _“If—to reason—”_ He couldn’t quite get the words in order.

“Do you see, now?” Hel asked Thor.

Thor shook his head. “No. This latest action of his is senseless. Jane Foster and Steve Rogers are good people, and there is no gain to be had by kidnapping them, much less so in such a violent fashion. And they are _mortal_. This is some mad plot of his, not some gainful scheme. Give up his location; if you insist on payment, I will see it done.”

“Death devours all secrets, Uncle,” hissed Hel, eyes narrowing. Skin stretched across her skull-like face. “Finality and oblivion are the terms, totality the condition, and no secret so eaten shall ever escape. Do not insult me.”

“ _Out,”_ said Natasha. Tony winced, but triggered it after a half-second of fighting back _noise_ ; she stepped out onto the grounds of Hel as though she were out for a noon-day stroll. The armour he’d made for her, he kept open behind her—ready to enclose her if, say, Hel suddenly transported them to someplace without atmosphere.

“Lady Hel,” said Natasha, and bowed deeply, without ever taking her eyes off of the dead god. “We aren’t looking for him directly. We’re looking for our friends.”

“Mortals.” Hel waved this off. “Ones unworthy of concern.”

“But worthy of kidnapping.” Natasha turned her head, just slightly. “Worthy of owing favours.”

“You _are_ presumptuous.”

“Perhaps. But there’s a lot of us. More than you—there’s as many of us, unique, as of all your different selves spread out across the world.” Natasha smiled, a hint of the conspirator about her. “A single snowflake may melt as it hits the ground. Ten billion snowflakes make an avalanche.”

“Do not speak to me of ice and snow,” said Hel, her tone so flat as to be pure death.

Natasha inclined her head. “Then let us speak of exchanging favours.”

Hel tipped her head to the side, and smiled. Her gums had receded, leaving her a grin like a skull’s, wide gaps beside each tooth. “Presumptuous and persistent both. State your bargain, and I will listen.”

“As I said, we don’t care where he is. We just want to find our friends.”

“One will lead to the other. I am not the Trickster, to delight in twisting bargains to the breaking point. I shall not hide where he has gone only to tell you where he will be. Ask something else.”

“When they part ways, could you tell us?”

“I am no seer, mortal. Death is the ultimate keeper of secrets; I do not need to seek them out.”

“Enough,” said Thor, before Tony could gather his brain up enough to try to stop Natasha from bargaining in earnest. “Lady Hel—”

“ _Queen_ , Uncle.”

“Queen Hel,” Thor amended, with the sort of expression on his face that made it look like he was humouring her. Not wise, but he was just arrogant enough. With the power that he had at his fingertips... it was easy to become arrogant, like that, _so_ easy... “If you will not take payment, then I’ll beg a boon of you, instead. But direct us to him. He cannot be left unchecked.”

“If Asgard wished to check him then they have had time.”

Thor glowered. “Asgard has been busy enough with the war.”

“And I have not?” Her eyes flashed with something other than darkness for the first time. “The Titan seeks to court _my Goddess!_ I shall see him ground to dust, and any who will work to this aim have my favour! I hide Loki for reasons three-fold, and will hear no more of your pleas. No. Go home, Prince. They will forgive you when you return to the front lines. Go home, mortals. Fight the real battle.”

_she has a goddess_

_...okay_

The thought was useful. Surprise helped fend off panic.

“ _Wait,”_ said Tony. Words crawled up his throat and threatened to choke him. _“Wait. I don’t—”_

“Breathe,” murmured Natasha, almost too quietly for him to hear.

“ _Whatever favour you want,”_ he managed. _“Whatever ‘we’ agreed—that couldn’t have been, me—”_

“It was,” said Hel. “As you will know when you have paid it.” Her long fingers tapped against the skull on her armrest, the sound of bone against bone. “You’ve overstayed your welcome here. This audience is over. Leave, or remain.”

“Niece—”

“Wait—” Natasha’s eyes dropped to Hel’s throne. The grey was creeping inward, closer—Hel vanished into it and was gone. “Okay, never mind—Tony, get us out of here.”

The armour was already enfolding her. Thor wore a dark expression—Mjolnir jumped into his hand and the air pressure dropped like a stone. _“If you do that I’m not bringing you along!”_ Tony warned him. Somehow the words came out in the proper order, despite the static rising in his brain.

“ _We still need him,”_ said Natasha, and aloud, _“Thor, stop it! Time to go.”_

Thor turned, his eyes full of rage and wounded pride. “I will not run from my brother’s offspring!”

breath gurgling in his throat. Blood in the lungs 

“ _You’re not running, you’re protecting us vulnerable humans,”_ Natasha told him, somehow managing to make it not sound sarcastic. _“And we_ need _you to put aside your pride and come.”_

But they weren’t—

He couldn’t—

With a frustrated look in the direction Hel had been, Thor lowered the hammer. “Then let us _go_.”

_i cant_

“ _Tony?”_ Natasha put one hand on his shoulder and shook him, gently. The grey was creeping inward—The edges of Thor’s cape vanished into it, and he suddenly knew that if all of Thor vanished into it, that would be the last they’d see of Thor, helping the war against Thanos or no. If he did— _“Stark. Activate the portal. Do this now.”_

There was _command_ in her voice that he hadn’t known she knew how to use. It was so much easier to just _follow_. Activate this subroutine, this other subroutine, that subroutine. Do as ordered. There was relief in obedience. Subspace wrapped around them—it would still be ripped apart, of course.

“ _Knock me out briefly. Then take us back to where we were,”_ she told him, and he did.

Their subspace bubble popped like a soap bubble as they fell into the Gap. Thor covered his eyes as they rose. It did nothing, Tony knew. The all-powerful Prince of Asgard, brought low by something greater even than he. Even the gods of Asgard died—were _meant_ to die. But Loki had found a way around it...

His efforts at pulling subspace around them were suddenly less frustrated, and he wrapped them all in a protective shield again. Thor remained curled over—was that a tear, making its way past his hand? Tony didn’t contemplate it. Something in the calculations was off. The world of ash and bone was not where they’d left it; the alien not-stars of the Gap were different. He picked the closest one and reverted them into a world in twilight, with no signs of life as far as the horizon stretched.

Natasha regained consciousness just as they hit ground, and Thor lifted his head. His eyes were gleaming, but he’d wiped away any signs of weeping—weeping for what? There was nothing in the Gap. It was Nothing, itself—the unmaking, the end, the devoured... the flip-side to reality.

“ _Calculate the route to Earth from here,”_ Natasha ordered him.

He already had it. He’d shown it to her. He started recalculating anyway. A second check was a good idea anyway—

—he was using it so he didn’t have to think, so that he had his mind full of something _useful,_ when it wasn’t really useful at all. But he had to—to think—

_no_

_NO no not—think damnit_

“ _I already have it,”_ he managed to say. _“I...”_ What was he supposed to do, if he wasn’t doing this? Make a decision. No, he couldn’t—he didn’t know the options—

—figure out the options—

“ _Able to think again?”_ Natasha asked.

He could shake his head and she would tell him what to do. Probably to take them back to Earth. Where they would all die— _no dont think of that_

He had to—he had to figure out options. Options.

Thor moved, and Tony’s hands were up before he could finish the motion, repulsors powered at max. But his inability to _think_ was slowing him down—Natasha threw herself between them, a mere step that still should have taken her too long to complete, and raised her own hands.

“ _Don’t!”_ she ordered. _“Tony, stand down.”_

“He has cause to be wary,” said Thor, completing his movement slowly—hooking Mjolnir back on his belt. “It's alright, Natasha. He cannot kill me.”

Not with a repulsor, he couldn’t. And that was what he’d gone for, in his panic. He’d need to reprogram the subroutines that governed weapon priority—except, no, bad idea at the moment. Bad idea overall; good way to accidentally annihilate himself before he got anywhere near Loki. Thor was—Thor had put his weapon away.

Thor said, “I swore I would protect you and do you no harm. I will keep that oath.”

“ _You swore other oaths, too.”_ Marriage vows. Vows of vengeance. Vows of grief.

It wasn’t like he hadn’t had it coming.

“And they were fulfilled. I cannot apologize for that, Tony, it would mean nothing.”

“ _Tony. Stand down.”_

He could just—she was probably—Natasha was always... competent. If he trusted her—

—chickened out of making his own goddamned decisions—

But he didn’t actually have a way back to Earth. He'd forgotten, in his panic. The relationship between Hel and this world wasn’t the same in this reality—the Prime Reality—as it was in their own; the Prime Reality, he knew damn well, was a lot more complicated. If they tried to go to Earth _here_ , would it be there at all? Whether it was or not, it wouldn’t be their own... Hel’s transport had been so quick that he’d not managed to get any sort of reading about how she’d moved them. He couldn’t just back-track.

_just fucking trust her steve asked you he promised_

Slowly, he lowered his hands. They didn’t seem to be quite connected to his brain. It was as if his every motion was done by remote control. He was far away, watching himself act through the distance induced by terror.

Thor lowered his head. “I will not betray your trust, Tony. There is no part of me now that would. I... regret... that you have seen my darkest aspect; it is not a capability of which I am proud.”

Tony didn’t know what to say to that. He teetered on a precipice: scream; blow Thor’s head off—or try to, anyway; trust Natasha... seconds ticked past and he defaulted to doing nothing. His hands were frozen at his side.

_think you moron think fucking think_

“ _I don’t know what you two are talking about, but we need to shelve it for now,”_ said Natasha, and something like relief flooded through Tony’s head and froze him all over again. _“When we were in your niece’s realm just now, Thor, she did something and the world changed._ You _changed. Did she transport us somewhere?”_

“Yes.” Thor inclined his head— _inclined_ ; it was too grave a motion to be considered a mere nod. “We were in one of the many branch realities, that is, a lesser copy of the Nine Realms. The... aspect of myself that existed there has, like all mere reflections of the whole, only limited knowledge. Hel transported us across realities, to—I know not how you call it. I am astonished you are even aware of it, Tony. I suspect it is my brother’s doing.”

“ _Nexus,”_ said Tony. He twitched with surprise. He’d... said it. _well done_ _“Prime, source, origin, centre... wellspring, confluence, alpha—you get the point.”_

“ _I do. So that means we’re a long ways from home—and we’ve lost the trail. Do you know the way back?”_

“No,” Thor answered for him. “The passage-stone would tell me, sure enough, were we still in Hel. From here, it would only point back to there.” Thor’s eyes were a hair too wide as he mentioned the Void. “Returning there would not be wise.”

“ _Then we need to find someone who does know. Thor—you’re the one with allies out here.”_

“Perhaps.” But he was frowning. “Asgard will be closed to me, of that I am certain, as will all of the other great pantheons.”

“ _But you have other allies.”_

“None that would look upon you with favour, I fear. But there are others, less known to me, who may be willing to hear you... if you will take us to them, Tony.”

He was looking at Tony with resignation, but it took Tony’s sluggish brain a full second to catch up: Thor expected to be refused. And Tony _could_ refuse him, if he chose—it was one more choice among millions: he could just _go_. Maybe it would _really_ earn Thor’s enmity; maybe he’d be chased across realities, reflections of the Thor chasing him down. But fuck Thor, Thor didn’t know—

Loki knew—

_what a fucking idiot_

He’d forgotten—his brain had slowed down so far he’d _forgotten_ —

Fuck, he wished he could forget.

_well you cant_

_gonna let natasha tell you everything to do_

But Natasha wasn’t telling him what to do. She remained silent, her armour still positioned between him and Thor, but with a tilt to her helmet that suggested inquiry. Goddamnit, she _knew_ exactly how much he couldn’t—couldn’t—

_just one thing_

He couldn’t figure it out. Complex problems became impossible. But he could do... one thing.

_steve told you to trust him_

_trust her_

_she trusts thor_

She didn’t know what Thor had done—

_i fucking had it coming_

Tony swallowed. The motion triggered chemical pathways in the brain—enzymes... hormones, too, neurochemicals, nervous energy released, a nervous tic fulfilled. _do one thing_ He could think enough to decide one damn thing—to decide the present. The future was gone. It didn’t matter. All he had to do was this one thing.

“ _Give me the coordinates.”_


	9. Knife and Hammer: 2.2

“Ow,” said a voice somewhere above Steve and to his left. “Ow. Ow. Ow.”

The repetition went on, with a kind of dull mindlessness. Steve was reminded of long nights spent hunched over a steaming bowl of water, struggling to breathe, telling himself, _One more breath._ And then, after it, _One more breath_. And again, and again, and again.

His chest rose and fell without him thinking about it, now, the serum having long since conquered his asthma, but the mere movement of breathing stirred something that felt like a thousand angry bees crawling inside his skull. Easy breathing turned into a gasp of pain, and his body curled inward, hands up—

The cool metal of his shield touched his skull and the buzzing quieted to a dull roar. The alleviation wasn’t total, but it came as a shock of relief anyway. He turned his face further against the shield's surface, feeling blessed silence spread, as though the shield were muting the pain—or, maybe, whatever was causing the pain. Grimacing, Steve sat up, doing a quick situation check. They were somewhere in the wilderness. The ground was rocky, without much scrub, and to his right the ground sloped gently downward. The rise in elevation peaked shortly to Steve’s left, where Loki was leaning against one of the two worn pillars that he’d showed them an image of, staring into a flat disk that floated in front of him. Reflected light played across his face; he didn’t look up.

Well, it wasn’t like Steve expected Loki to help. He got to hands and knees and crawled the four feet across to Foster, who was huddled in on herself, shaking. The shield came off of his arm clumsily—his ears were still ringing a bit—and he pressed it toward her. She leaned in to it, and then as the vibranium worked its miracle she sort of crumbled toward it, not uncurling from her huddle, but pressing herself up against the shield as much as she could instead. As tiny as she was, she could easily curl up beside it. Thankfully, her pained repetition stopped.

He gave her a minute, and himself a minute too, to catch his breath and let the serum make short work of the lingering headache. The air here was crisp and cool, but pleasant; the sun, sitting at about halfway from the horizon, kept it just warm enough. They were definitely at altitude, though... or, he amended ruefully, the atmosphere of this world was just naturally thinner than Earth’s. It wasn’t dangerously so, but he could feel the difference every time he breathed in.

“Oh my god, this is amazing,” Foster mumbled. She lifted her head, uncurling slightly away from his shield, and squinted at him with an unnerving intensity. “I need to borrow this when—when we get back, I need to run _tests_ , god.”

“Uh. Nothing that will damage it.”

“No,” she said quickly, but he could _see_ the wistful look she shot the shield as she climbed to her feet. He grabbed it from the ground before she could. “Of course not, I wouldn’t—I just. I think that it must have actually grounded out some sort of energy, something left over... This could have a real effect on the portals, I mean, not that—um.” She shut her mouth abruptly, glancing up at Loki.

“Loki?” Steve said, raising his voice a little. He settled the shield back onto his arm, checking the straps.

Loki’s eyes snapped open and the light from his disk vanished. For an instant Steve thought he looked lost, hollowed-out, but then the expression vanished, so smoothly that Steve might have been mistaken. “Up and about at last, are we?” he drawled.

“You know, I met a human sorcerer who managed to travel through realities a lot better. Smoother. Easier on his allies.”

“And no doubt flashier. We require secrecy.” Loki pushed himself off from the pillar and beckoned them forward; the disk he’d been holding had somehow disappeared entirely without Steve noticing. “Come. You should feel honoured, for this is a secret place indeed. No mortal has ever set eyes upon it before.”

Steve glanced down at Foster, and lowered his voice. “Your AED working?”

She glanced down at it hurriedly. “Yeah. Oh! Yeah.”

“Right.” He hesitated. “Dr. Foster, if we have to get out of here in a hurry...”

“I will come up with something,” she said firmly. “I’m not a, er, sorcerer, but I know the theory better than anyone else at SHIELD except Stark. Probably better than him, too.” Her nose wrinkled.

“Okay.” Steve took a deep breath, and stepped forward.

“If you’re finished?” Loki raised his eyebrows, and then turned, pivoting imperiously on one foot, causing his coat to flare out behind him. At least he wasn’t wearing his horned helmet. “Come.”

Steve gave Jane a hand over the loose rocky slope to reach the peak where Loki stood. It looked down onto a flattish area, where ruined stonework could be seen jutting out around a pond full of water. The pond itself was slightly murky, with scum floating around the edges of it, and the occasional plants that had grown into it and also over the exposed stonework. At least, Steve thought it was stonework. If it hadn’t been for the overall shape of it, a perfect circle, he might have thought it just coincidence. The two pillars were the only parts of the Temple that still stood upright.

“Trial number one,” said Loki. He sounded contemplative. “Finding the entrance.”

Steve glanced past the pool. There was more rock heaped up there, covered with plants. Was it just natural rock, or was that a collapsed building? Impossible to tell. “I think we could just walk around, at this point.”

“Nooo,” said Loki, drawing the word out. “Because this pool doesn’t make sense.” He stared into it.

Steve stared into it as well. Steps ran around the edge of it, leading down in concentric rings until the depth was too great to see them anymore, which was at least seven feet on the near side. The water wasn’t terrible, but it was deep enough that he couldn’t see the bottom.

After a minute had passed, Foster asked, “Why doesn’t it make sense?”

“The gods who worshipped here worshipped the sky,” Loki replied absently. He stepped forward and toed at the water with one boot. “They didn’t bother with water.”

“Gods... worshipped here?” Foster sounded confused. Steve couldn’t blame her... but he thought he also might know how Loki would answer.

“All beings respect those with more power, except the very stupid. The merely stupid sometimes take it to ridiculous extremes—even among gods.”

 _On the other hand, maybe he has a different view of it,_ thought Steve.

Or maybe he was just lying.

“Maybe they used it to clean themselves off before they entered the temple?” Foster suggested.

“And here I thought your science was the art of observation. The pool is too deep to be practical for bathing.”

Foster flushed. “Well, I don’t know, you all seem to be _giants_ ,” she said snidely, and then immediately her eyes went wide.

Loki grinned at her, a baring of teeth. “Quite. But, no. Those who lived here were around your height.” He stared down at the water again. “It is the entrance.”

“Underwater,” said Foster skeptically. Steve shared her skepticism. If these people worshipped the sky, why the heck would they put the entrance to their tunnel underwater?

“Yes.” Loki made a gesture at the pool—not magic: a command. “In you go. I imagine it will be at the very bottom.”

“What, you can’t just pull all the water out?” Steve asked, shifting, but he was already running through mental preparations. Getting pond scum all over his suit wasn’t high on his list of things to do today, but it would be stupid to go in without its armour—and even if he took it off, he’d still be covered in scum himself. If he had to do this, it would be fully clothed.

“Certainly I could. But I doubt doing so would aid us in getting into the temple.” The grin on Loki’s face was wide enough that Steve wasn’t convinced he wasn’t just being a jerk.

_Damn it._

He slung his shield off of his arm and onto his back, where it wouldn’t get in the way while he was swimming, and looked at Foster. She gave him a tiny nod.

“Clock’s ticking,” Loki remarked.

Steve rolled his eyes and waded in. The water was _cold_ , damn it. He forced himself to ignore it. It was nowhere near as cold as the giant river that the fish-demon had lived in. This cold wouldn’t kill him in minutes; it was just really uncomfortable, especially as he stepped far enough out that it came up past his waist. He waded further out until it was chest-height, and he could only barely see his feet, and then took a deep breath and dived.

Underwater, his vision, of course, was blurrier, and the murky water stung his eyes. He flipped over and swam downward at an angle, following the line of the stairs as a guide. The light faded, making it more difficult, but he could still make out shapes by the time that, when reaching out in front of him for his next stroke, his hand contacted stone instead of more water. He fumbled to orient himself again, and squinted at the dim, blurry surroundings. The pool was maybe fifteen feet deep, though his estimate of distances wasn’t the best while swimming underwater. He swam further down, until his face was no further than a foot from the bottom, and then kicked off the last stair, searching the bottom more with his hands than with his eyes.

His lungs were just beginning to burn in that mild way that told him his body had noticed he wasn’t breathing—plenty of time left. Steve forced himself to _take_ time and move in a methodical pattern. If Loki serious about the entrance being down here, he didn’t want to be diving up and down for half an hour because he’d been sloppy about it. No, if he could find whatever there was to find on the first go, so much the better.

His hand brushed over something that was a different shape than the rest; he squinted, and could make out a sort of raised stone. Feeling out with his fingers told him that it was just as slimy as the rest of the stone down here, but perhaps an inch higher; there was a symbol carved in the top of it, and a groove that ran around the sides, near to where it fit against the bottom. He tried to grip it with his fingers, enough to try pulling on it, but the stone had been worn too smooth and covered by too much slime.

Pulling his shield from his back, Steve tried wedging it in the groove, instead, grimacing as he did so—forget his suit, the straps on his shield were going to be hell to clean off later. The burning in his lungs was growing more urgent now. The edge of the shield caught... not quite enough. He could use it as a lever, perhaps, but that meant he couldn’t push off against the bottom with his feet—he tried, slipped, and went somersaulting around in the water before he could regain his equilibrium with a scowl. No doubt Loki was up there, dry and laughing at him.

He repositioned himself, grabbing hold of the far side of the stone, and jammed the shield against it, grinding it back and forth so that its edge cut into the rock itself. Then, hoping that he wouldn’t just break the top off—in which case Loki would have to come down here and magic it up himself, protests be damned—Steve braced his feet again and pulled upward on the shield, using it as a handle this time instead of a lever.

The stone groaned and rose about an inch, before stopping with a _click_ that was clearly audible through the water. Steve tugged further, and side to side—it turned to the counter-clockwise direction and he kept pulling it, a quarter-circle around, until there was another _click_. Then up again, and this time holes appeared at the bottom of the stone as it rose. Immediately the slime nearest the stone was pulled into them as the water rushed down.

Steve pulled his shield out and waited a moment to see if the stone would sink on its own, but it remained up. Good: he now urgently needed air. He kicked off toward the surface and broke through with a gasp, shaking water from his face.

He wiped scum away from his eyes and looked around. The water level was visibly dropping, and he could feel the pull of the current, but the holes hadn’t been that large; it shouldn’t be draining _this_ fast. At the top of the stairs, which were now steadily being revealed by the decrease in water, Loki stood with green fire playing about one hand. Question answered, maybe? Steve eyed him, and gave a worried glance to Foster, but she was standing off on the other side of one of the pillars. When she saw him looking back, she waved.

The current tugged harder at his boots—he didn’t want to stay out here. Steve kicked out for the stairs, instead, and by the time he reached them the water level had already dropped halfway.

“So much for not being able to drain it with magic,” he told Loki.

“Hmm? Oh, this isn’t that,” Loki replied, shutting down his spell. “I multitask, Captain. Time is precious.”

“Right.” Steve stepped partway up the stairs, feeling and hearing his boots squish. The stains of pond-water tickled his nose, too. His skin was going to itch like hell when he dried.

“Well done, however,” Loki added, stepping past him down the stairs. The water had now nearly entirely drained away, and it was shallow enough to see how: the bottom stairs, and the bottom itself, had holes riddled throughout, until they were more like a grate than steps. Nor was the stone circle that Steve had raised the only one such. There were three others, set evenly about to correspond to the corners of the pool’s bottom, which was a perfect square.

Foster came around from the other side of the pillar as Loki stepped down among the muck. She was frowning, biting her lip.

“You okay?” Steve asked, keeping his voice low.

“I’m... fine.” It was obviously a lie, and it was evident she realized how fake she sounded in the next moment. “I mean, he didn’t do anything, but, you know.” She blinked several times. “I’m fine. Why would people who worship winds put a secret entrance underwater? And leading down? I’d have thought something like Stonehenge, on a mountaintop...”

“Such would allow them to see their gods, it is true,” called Loki. He was crouched down, examining one of the raised circles of stone and seemingly oblivious to the way he was getting left-over pond scum halfway up his fancy coat. “But it’s generally inadvisable to remain beneath the eyes of gods for more than a moment. We might just take notice.”

“Oh,” said Foster, sounding distinctly unhappy about this.

“Of course, there’s always the other option,” said Loki, tracing a geometric shape in the air with his fingers. “Religion is oft the province of the irrational.” The disk of green fire that allowed him to fly blazed to life about his feet, and all four stone circles twisted clockwise with loud, protesting noises. Then they fell back into the ground—and continued dropping, along with the rest of the former pool’s floor, revealing a pit below. Steve held out a hand for balance, and to make sure that Foster didn’t fall in. From the edge he could see, it looked like the opening inverted on the other side—a pyramid of space, below. The drop was about ten feet from the last step, making it shallower than the pool above it.

“Hmm,” said Loki, and cancelled his levitation spell. He landed lightly on his feet, without sign of effort, and walked out of sight.

Damn it. “I can jump and catch you,” Steve offered to Foster. “Uh... if you don’t mind.” He gestured at himself—his hands weren’t exactly clean.

She was peering over the edge with some trepidation; he suppressed the urge to haul her backwards. “Um, yeah. I mean, I don’t mind. If I tried to go off the ledge I’d just slip and get covered anyway.”

“Right. Jump right after me, okay? It’s not a good idea for us to split up.”

She laughed nervously. “No objections there.”

Steve jumped, landing firmly and steadily. There was no slime down _here_ , somehow, and the floor was perfectly dry and covered in a thick layer of dust. Where had the water gone? More importantly, where had _Loki_ gone? Steve glanced around ever as he positioned himself and raised his hands to catch Foster, but he couldn’t see Loki anywhere. The thought of him lurking in a corner was not reassuring. It was too much to hope that he’d just _left_ —and it wasn’t really a hope. Steve didn’t think that even Foster would be able to turn her tiny, improved AED into a full-blown portal. Unless this world had some other energy source, their best bet was actually to _stay_ with Loki. For now.

But they needed to make sure that they retrieved the Mind Gem ahead of him—and that once they had it, one of them could learn to use it quickly enough to keep Loki from simply taking it away from them.

He caught Foster and set her on her feet, trying not to feel bad about the way he got dirty hand-prints on her coat. She was already pretty dusty, which was also his fault. Well, no. It was Loki’s fault.

“Thanks,” she said, a bit breathless.

“No problem, Doctor.”

“Oh, call me Jane.” She grimaced. “We’re stuck together, after all.”

“Steve, then.”

“How touching,” Loki drawled, padding out of the darkness; Steve wasn’t certain if he’d been there the entire time or if he’d literally appeared from the shadows. “Well. We’re certainly stuck in this place, unless the next step can be discovered.”

“How many ‘steps’ into this temple are there?” asked Steve.

Loki shrugged. “If I knew, I’d have completed them all.”

“Okay, um,” said Foster, staring at the ground. Her lips pressed briefly white. “We need more light, then.”

Loki gestured and cool white light filled their surrounds. These were more peculiar than Steve had at first imagined. The floor wasn’t actually flat—rather it curved down, an enormously shallow curve, so that they were standing more or less at the top of an extremely subtle hill. The roof overhead extended downward at first as sharply as the stairs had above, but in pyramidal squares, rather than circular ones. This steep descent stopped about five feet above the floor, and the roof flattened out... or, not quite: it curved in a similar way to the floor, so slightly that it really did almost look flat. It was mirrored, too—although enough dust clung to its surface that it did not blind them all with radiance.

“Wow.”

“Yeah.”

Loki ignored their awe. In fact, given that he’d been the one to kidnap them and bring them along, he now seemed content to ignore them entirely. “It must be somewhere below us...”

“We need to—we shouldn’t be standing on this, oh my _god_ ,” said Jane. “Oh my god.” Her hands and arms fluttered, like she wanted urgently to move but was paralyzed in place, unwilling to step anywhere else upon the glass.

“What?” asked Steve, sliding his shield back onto his arm. Better to have it in the closer ready position.

“It’s a telescope!”

“It—what, really?” Steve squinted at the floor.

“Do you have any idea how impossible it would be to make a single lens this—never _mind_ that! It probably still doesn’t work, there’s no way it could work, but we shouldn’t be _standing_ on it!”

“It has survived some eras, it will survive us,” said Loki. But he did sound intrigued now. He lifted a boot experimentally and stamped down.

Jane grit her teeth so hard that Steve could hear it.

“You may be correct,” said Loki, grudgingly. “Well. You are not the only one who studies stars, mortal, although this is a far more primitive method than those used in Asgard. I suppose I should have expected such from those who would worship the gods above them.” He shook his head. “Very well. Up you go.”

Loki’s power wrapped around Steve’s feet, yanking him upward. Jane shrieked as the same happened to her. Steve pinwheeled, lost his balance, and fell head-over-heels—the spell dragged him higher and left him dangling. First things first—Jane was fine, also struggling—Loki, the bastard, had lifted himself into the air on one of his green disks.

“Housekeeping,” Loki remarked, and he uttered a chain of sounds that made Steve’s ears hurt.

The effects were apparent immediately. The light of his earlier spell reflected from the mirrored ceiling, doubled and trebled in power as all the dust in the chamber vanished.

“You’ll burn out the focus!” cried Jane.

“Don’t be foolish. You think it chance that their lens and mirrors still curve as they should? Do not judge the works of gods by the frailty of your mortal inventions, Lady Foster.”

Steve rolled his eyes. “For God’s sake, you’re the one who kidnapped us here. If you want our help, act like it.”

“You’re not being much help at the moment.”

“The lady just figured out that it’s a telescope for you. Stop dangling us midair.”

Loki made a sour face, but the next moment the light had dimmed and his lifting spell was reversing itself, with courteous slowness, not simply dumping them on their heads but actually setting them on their feet. Jane brushed herself off, looking shaken.

“Relax,” Loki told her. “The petty gods that built this temple worshipped fearsome skies. If this telescope withstood _their_ gaze, then your footsteps will be as nothing.”

“You’ve clearly never spent all night polishing a telescope lens,” muttered Jane.

“You’ve clearly never had the benefit of magic.”

It did seem true, Steve had to admit. Loki had wandered around plenty—probably just to be a dick to Jane—and his boots were just as muddy as Steve’s, although hardly as saturated. But Loki wasn’t leaving behind footprints, and—Steve took a step, experimentally—neither was he.

Cautiously, almost cringingly, Jane leaned down and prodded at the now crystal-clear surface of the lens with one finger. Steve examined the spot, but even to his super-human vision, she hadn’t left a smudge. Well, then.

Making a somewhat dissatisfied noise, she turned and began peering around in other directions. “There have to be controls somewhere.”

Keeping an eye on her in case she decided to wander off in search of said controls—because it was still a bad idea to split up—Steve turned to Loki. “Who _were_ the people who built this place? And who did they worship?”

“A petty pantheon,” Loki dismissed. “Perhaps unheard of even upon Earth... and everyone travels to Earth at some point; humans are _easy_.” The sneer in his grin made it clear exactly how he meant _that_. “ _Worship_ of one’s betters is restricted to those who not only have betters but who resign themselves to that fate. No self-respecting god worships another, but there are sadly those who lack this realization.”

That was a bit of philosophy that... probably was neither valid nor useful, coming from the person it did. Steve resolved to remember it, but ignore it. He made a ‘hmm’ing noise and gestured for Loki to continue instead.

Loki eyed him a moment longer—giving him more time to take the bait? Steve kept his mouth shut, though, and Loki deigned to continue. “To worship is to bow down and agree to let another sit in judgment over you... in all things. To consign your soul. There are any number of powers who _crave_ such recognition. I admit, I’m not sure which, exactly, these small mountain-gods worshipped—the one text of theirs that I acquired called them Judgments, suiting name to purpose, but they were hardly well enough described to match them to a true name. I suspect the gods here were ignorant of it, themselves. And why not? They thought these Judgments beyond them and were resigned to staying that way.”

“Okay,” said Steve, trying to bury his impatience. Loki was Loki, and he was so _obviously_ goading Steve that the best course was just to ignore it and leave him frustrated. “So where does the giant telescope come in? It’s in a temple, it must have been important to their beliefs.”

“The writer of the text I found had a constant fear of being watched. In such a situation...” Loki gestured at the lens beneath them.

So they had built something to use to watch back. Huh. Was it really a telescope, then? Or was it something more mystical—or more scientific, like Jane’s device that blocked lower-case gods from overhearing their names? Steve supposed it could be all three.

“Oh!” said Jane, and Steve jerked his head around to see her pull her hand away from the mirrored roof, then reach back out to it. “Huh.”

“Problem?”

“It’s an interface.”

Loki went in the same direction as she had and raised his hand to the ceiling. Being over a foot taller than her, he wound up standing beside the mirrored portion, rather than directly under it. It didn’t change in any fashion that Steve could see, but when Loki said, “Ah,” Jane made a frustrated noise and said, “Don’t do that.”

“It’s not exactly complicated,” Loki said dryly. “There is a secondary interface, if you must.”

“Hm.”

Steve resisted the urge to put his own hand to the ceiling and try to figure out what either of them were talking about. He didn’t know any more about stars than how to use them to navigate through European wilderness, though, so he let them to it.

At length, Loki made a triumphant noise, Jane made a noise that sounded suspiciously like a growl, and an enormous shudder ran through the entire ceiling, the mirror wobbling like quicksilver—and then, even more like quicksilver, beginning to flow. _Upwards_. Ripples ran through the lower, mirrored portion as it flowed toward the opening and up the pyramidal incline, out the top... Steve crouched, and leapt straight up, looking for an idea of where it was going. The answer was: all around them. Above the pyramidal opening, an enormous silver bowl was drawing itself up and around—the wide open rocks providing previously unrealized support, not that the quicksilver material seemed to need it. In comparison to the sheer size of the inverted dome above, and the lens below, the opening that had been the bottom of the pool was little more than a pinhole opening for a camera.

“Not so complicated to sort out,” said Loki. “Really. Remarkably primitive.”

Steve glanced down at his feet, and around to the far walls of the room. The lens in the floor was still all there was. “Do we need to go back out?”

“No. It’s still beneath us. Patience, Captain.”

“It’s not _that_ simple,” Jane muttered.

“It’s precisely that simple. They are worried of being watched, yes? This is designed to detect exactly that. These Judgments fell to oblivion long ago, I’m quite sure—all that remains is to prove it to the apparatus, and it shall let us pass.”

“It’s daytime,” said Jane, her tone fixed and level. “It’s not going to see anything except the sun.”

Loki blinked, looking thrown. “You’re referring to... optics?”

“Yes.”

“Surely it doesn’t use such primitive—oh. It does.” Loki pulled his hand away from the ceiling, then stared at it, wriggling his fingers back and forth.

“Yes, it does,” said Jane impatiently. “So opening up the bowl doesn’t do anything except oversaturate it. We need to wait until night-time, and in the _meantime_ —” She pressed both palms against the ceiling, and made a triumphant noise as the mirror flexed beneath her hands. Ripples formed again, and the quicksilver began to rush back to where it had come from.

“You only figured that out because I showed you how,” muttered Loki, earning himself an incredulous look from both Steve and Jane.

“ _You_ —you know what, fine. In the meantime, _I_ am going to study this.”

“And I am going to do something useful with my time,” snapped Loki, bringing his hands together. Just before his fingers could touch, a roil of poisonous green power erupted between his palms. It flashed up and over him, stretching the air like a rubber band—and then, snapping: the air pressure rocketed back up, and with a _bang_ , Loki disappeared.

“Loki!” Steve shouted, uselessly.

“Did he just—?” Jane gaped at the empty space that Loki had left behind.

“Left, yeah.”

“Right. Okay.” She shook her head. “That looks different from outside.”

Being near the teleport, or whatever it was, still _felt_ wrong. The hair on the back of Steve’s neck was standing on end and all his skin felt like it was stretched too tight over his bones, a hair away from cracking open and bleeding. He shook his head and ignored it; there were more important things to focus on. “Yeah, well. It’s not a way _we_ can get back home. Doctor—Jane. This mirror, uh, telescope. Do you think you could use it to figure out where we are, maybe get us home? Or at least get us somewhere else.”

There were allies out here, somewhere. There were people like the Chief Magistrate, who were willing to help strangers, to lead by example, and to be the first to show faith. But even if the Chief Magistrate was a rare diamond in the rough, getting to somewhere with _people_ , of any sort, would still be a good first step. _People_ meant transport. Even if this telescope couldn’t get them home, if it could get them partway then it might be enough.

“I don’t know,” said Jane. One hand crept up to her mouth; she chewed on a hang-nail as she thought, then seemed to notice what she was doing, and took her hand away and hid it behind her back. Nervous habit, Steve guessed. “I don’t—okay, look. It’s a telescope. I mean, it has some reconfigurable elements, but—it’s a _telescope_. That’s fundamentally what it is.”

“So that’s a no.”

“That’s a _maybe_. This stuff isn’t like extremis... I don’t think it would hold smaller shapes very well. It’s meant to be _big_ and spread out. The moving agent is all external. I think.” She shoved her hands into her coat pockets. “But it might be reprogrammable.”

“You've got until sunset to figure it out—however long that is.”

“Alien world.” Jane sighed wistfully. “At least I’m in the best part of it.” She blinked, sniffed, and blinked a bit more rapidly.

“...Right. Um.”

“It’s—never-mind.” Jane wiped at her eyes. “Never-mind. I’m fine.”

Since he hadn’t suggested that she _wasn’t_ fine, Steve had no idea what to say to that. Being on first-name terms with somebody because he’d been kidnapped with them wasn't actually helpful for knowing what to say to her. She was a civilian, but she was also a top-tier scientist—if he just left her to her work, would she distract herself? Or would she begin to fall apart, like Tony had?

The latter decided it. If he had asked, sooner... he hadn’t seen the signs that Tony was having issues; but Jane was a civilian, it had been an extremely traumatic day, and here she was. “Are you... okay?”

“I’m _fine_ ,” she insisted, turning away, but she was still rubbing at her eyes, and her back was ram-rod straight. “I’m—Darcy’s probably _dead_ , and it’s my fault, and I’m _fine!”_

Ah.

“Until we get back, we don’t know,” said Steve, trying to be both gentle and confident. “Ms. Lewis is young and tasers _are_ non-lethal—”

“It was fucking illegal, okay?” Jane snapped. “She had an illegal taser that she amped god-knows how high because she was scared of getting mugged in New York. It was—I’m sorry, you don’t deserve that. You actually don’t deserve that, it’s Loki. Just—look, just let me work on this.”

“It’s not your fault, no matter what,” Steve tried. “It’s Loki’s fault.”

“And I’m the one who got us all involved with _that_ , so.” Jane pressed her hands against the ceiling. “I’m fine. I need to work on this.”

“Jane—”

“I _need_ ,” Jane said loudly, dangerously, “to work on this.”

Right. Steve held up his hands in a sign of surrender that she couldn’t see. She was fine.

They were all just fine.

 

* * *

 

It was night where they arrived, stars gleaming across the sky like jewels across a tapestry, so bright and clear that for a moment Tony thought he’d miscalculated, and had to check that the debugger was still keeping the errors under control—but, no, they weren’t stuck in the Gap. Natasha and Thor’s reactions, or rather the lack thereof, confirmed this a moment later. These stars were natural, if made inhumanly perfect by the absence of all human light pollution, and possibly something wonky going on with the upper atmosphere.

Star charts clicked the location into place a moment later. _“This is Earth.”_ Earth, around thirty degrees south of the equator, and mid-autumn.

“ _But not our Earth,”_ said Natasha. _“Who are you taking us to meet, Thor?”_

“In a sense, the Earth herself,” said Thor. He sounded subdued as he stared at the sky, head tilted back and his shoulders down. “This is the truth of your planet, here in the centre of all realms. All others are mere reflections, but this is the primordial Earth, and here dwell beings that even Asgard would count as ancient.”

No satellites. No signals bouncing through the atmosphere. If there was something dwelling here, humans—advanced humans, anyway—weren’t among them.

“ _Living with humans? Or apart?”_

Thor shook his head. “Mortals do not dwell in the ‘Nexus’, as Tony put it. You may be the first to step foot in this place since the beginning of time.”

“They aren’t,” said a woman’s voice, and Tony’s sensors clamoured warnings at him as something that hadn’t been there was suddenly right in front of them.

_end end end_

Tony managed not to engulf them all in bloody conflagration as Thor bowed, reverently, and said, “Great Mother.” Except that was not all he said; the Allspeech usually worked so seamlessly that it was difficult for Tony to even detect it being spoken, but in the presence of this woman it seemed to split, a hundred languages layering over each other, each with a different name and all of them meaning the same thing. “Gaea,” was what Thor had said, and at the same time, “Domnu”—and _Nana, Papa, Erce, Terra, Yo, Aditi,_ on and on.

Her skin was olive-brown and her hair a rich brown with undertones of red, but in the moment that Thor spoke her title, Tony could see more than that: a taller, rounder woman with hair and skin the colour of the night sky; a broad-shouldered woman with hair blonder than Thor’s and a milky-white complexion; a short woman with bone structure pointing to south-east Asian heritage; a hundred and more of every variation in-between—and then the last syllable left Thor’s lips, and the strange second-sight was gone. One language, and one image, were all that remained.

“You have disappointed Queen Frigg, Thor,” said Gaea. She sounded disappointed herself, and her face changed with the emotion, showing a weight of weariness and sorrow.

“I suspected as much,” said Thor, looking ashamed, but to his credit he met her gaze evenly. “But there are many who stand on the front lines. There is no one else to police my brother.”

“The Outsider is not your brother. You would do well to remember that in the days to come.” She shook her head. “Asgard is not my concern, and I will not gainsay Hel to help you find him. We _cannot_ have civil war.”

“I have a duty that I must follow.”

“You have a duty to take your place on the battle line,” Gaea said sharply, with a voice that echoed from the cliffs surrounding them. But then her expression softened, again, and Tony was struck by the immediate resemblance to Frigga. Frigga, whom he had, for a minute, regarded as his own mother, so much that he had wanted to sit down at her feet like a child... “Will you not return?”

“I have a duty,” said Thor stubbornly.

“ _Out,”_ said Natasha, and she stepped free of the armour. “What about us?”

Gaea looked at her, and she had the same trick as Frigga did, alright, looking right through you and seeing everything there was to know—Tony cringed away from the thought of being looked at, and barely managed to avoid physically cringing as well.

“You are mortals of the current epoch, and therefore under my protection,” said Gaea. “I can send you home.”

“No. What if _we_ want to pursue Loki? He’s taken our friends, two other mortals—it’s our right.”

“Persistent,” Gaea noted, and shook her head, but not in denial. Amusement? Acknowledgement? Regret? “ _Go_ , Thor,” she commanded, and Thor was gone.

Just like that, without even a wisp of dimensional slip to mark his passage.

Tony locked his knees, before he could fall over. Just like that. A being... far _beyond_ Loki. If she—she—

_under her protection_

“Time will not touch you here,” said Gaea. “Both of you are weary, and in need of solace. Take it here, for a while. Let other worlds stay frozen outside.”

It was like Frigga all over again, and not. It was the complete inversion of Kuan-yin—she’d had the image and never the _presence_ of a mother. Natasha nodded, her eyes wide and bright, and stepped forward—then turned, faltering, as if remembering that Tony was still there.

“Come,” Gaea coaxed him, even as she reached out her other hand to clasp Natasha’s, a mother holding on to her small and beloved child. “My protection is all the armour you require in this place.”

Heaven help him, but Tony _believed_ her. Panic reared again in his head, paralyzing—he shouldn’t do this. He shouldn’t? He couldn’t move.

“Come, Tony,” Gaea said again, stepping forward and taking his hand. He felt very small, although she was only a few inches taller than him. The armour melted away from her, vanishing back into subspace without so much as a whisper—he could see it in there, registering in the scans. Just enough remained to give him clothes—rough clothes, workshop clothes, clothes he hadn’t worn in... months, god, it felt like so much longer.

She led them up a wide, rocky space that hadn’t been there a moment before. It wasn’t a path; that would have implied something designed, something mechanical: this just happened to be a slope shallow enough to walk on.

“Who are you?” asked Natasha, her voice thick. “How are you making me feel this?”

“I am the source of the Earth, and protector of all my children who reside upon it,” said Gaea, her voice low and soothing like a lullaby. A sad lullaby—there was grief, beneath the reassurance. “So often you are beset, without and within, and there is nothing I can do. Here I can do something, small as it is, and so I shall.”

“I don’t want you in my head,” Natasha mumbled.

“I’m not. Consider your own thoughts and feelings, and you will know this to be true.”

Natasha’s voice became, if possible, even tinier. “I—I saw things.”

“I know, daughter. I know. And I cannot take that from you—I’m sorry.” They all paused, and Gaea drew Natasha further in, an arm around her shoulders, and pressed a kiss to her brow. “But it will _not_ destroy you. On that you have my promise.”

_where were you when_

The flat rock drew around the side of a cliff-face, and the roar of a distant waterfall gave way to observance of the immediate thing: a thunderous tide of water pouring over a cliff eight metres above, and dashing down against rocks far below. Gaea raised her hand—the one still holding Tony’s—and dragged both their hands across as if shoving aside a curtain; a gap parted in the waterfall, wide enough to admit them all, and they continued forward, through a mist that settled gently on their skin.

Beyond was an enormous cave, which looked almost like limestone except that there were also glittering crystals growing up out of the floor in bunches, enormous geodes smashed open to expose their shining gems. A rough, almost accidental stairway wound down from the entrance to a dark pool that sat in the centre of the room, stalactites clustered above it. The roar of the waterfall seemed diminished once they were inside, although it was right behind them.

Below, beside the pool, stood a circle of tall figures clasping hands. Gaea was among them, her face serene and her eyes closed. This did not change—none of them did—as one of the figures... stepped back—and yet _didn’t_. It was like having double vision, but both images were solid—the figure simply split into a duplicate, without ever becoming distorted or losing shape. It began to make its way up the stair to meet them.

Gaea—the one with them, the one holding Tony’s hand—turned, and there was another stair, lined with glittering points of reflected light. She tugged them gently onward, and they came to a second cave that was smaller and dryer, with a rough but somehow comfortable-looking wooden table and benches set in the centre. Without letting go of their hands, Gaea led them over to the further bench. This was the one facing the door, and it shouldn’t have made any difference when Tony knew reality could just be bent around them to make a new door, but somehow he felt more reassured by the positioning as he sat.

He wanted to rest his head on her shoulder, curl up, and sleep.

The figure from below that had split and duplicated emerged through the doorway after, followed by another one, no doubt also a duplicate from below. The first was cloaked; a glint of metal beneath its cowl hinted at a metal mask, but that could also have been its face. The second was entirely golden, a sexless, faceless being, but with the hint of something larger and darker looming behind it...

“Go away,” said Gaea to the first. “This does not concern you.”

“Go, or you will have your son eat me?” Despite the lack of a face, the cowled being managed to shoot a visibly contemptuous glance at the golden one beside it. “I know your philosophy, sister. You will save what _can_ be saved... and so you will hardly be doing anything to _me_ at this late hour.”

“Who are you?” asked Tony.

The words came out in a whisper, startling even to him. Gaea squeezed his hand beneath the table, and he looked down, belatedly realizing he’d been staring at the golden being. It was like staring into the sun. Spots danced across his biological vision, before extremis repaired the damage.

His question was ignored, but his presence wasn’t. “So this is the Outsider’s pet...” A cruel smile worked across that unseen visage—unseen, and yet Tony _knew_ its expression, with all the soul he didn’t possess. He heard Natasha stifle a gasp. He should be standing. Shouldn’t he? Ready with weapons—he could call the armour out of subspace—

_useless useless useless_

He stayed seated.

“You are in my home, and they are mine to protect,” said Gaea. “I will not need my son’s assistance to deal with you, Chthon.”

“Hah.” Chthon turned to leave; the other being, Gaea’s son, followed. But Chthon stopped before the doorway. “Little Loki’s plan will never work. He thinks that the Titan can be _killed._ ”

“Perhaps, perhaps not. It costs nothing either way. Now, leave us,” said Gaea, and the world became strange.

There was more to this place than a cavern and some tables and benches; there was more to the three _beings_ around them than their all-too-human appearances. Night roared around them, stars-that-were-not-stars, and they were not in the Void, the framework, but they were not in any single place within it, either; realities layered over each other and in every single one they were here-not-here, Gaea’s protection wrapped around them, an adamantine wall ten thousand light-years thick and the only thing standing between them and the infinite hatred that burned out at them from the masked figure just across the room.

“Hah,” Chthon laughed again, and stars quaked and trembled.

Then he left. Gaea’s son followed close behind.

A door closed over the entrance to their small cave, and a fire lit in a fireplace that hadn’t been there before. It cast a cheerful yellow glow, reflected back purple in the dazzling geodes that decorated the cracks between walls and floor.

“Who _are_ you?” asked Natasha. Tony looked past Gaea to her; she was still. Calm, aside from the tremor in her voice. Not shaking, like Tony was.

“The Eldest,” said Gaea, standing. “The first race of gods.” She squeezed Tony’s hand and let go—and yet didn’t; they were still safe beneath her protection—and dropped a kiss to both their foreheads simultaneously. The split did not seem wrong. Tony didn’t bother examining it in his head. He watched as she stood, went over to a basin that hadn’t been there until it was, and pulled out two cups, filling them with water and carrying them back to the table. One she set down on the edge; the other, in front of Natasha.

“The water will not change you, nor heal the damage done by such sights as you should not have seen,” said Gaea, “but it can wash away the immediate harm, and you are capable of healing from the rest in your own time. Will you drink it?”

Natasha reached out, setting her fingers lightly around the cup. “Why do I trust you so much?”

“My title is not meaningless,” said Gaea. “I am, in many ways, your parent... the parent you should have had, Natalia, if the Eldest were truly omnipotent, omniscient... but although we are not, we _are_ more. All parents are part of me: all who guide, who protect, who nurture. Any who have experienced such, or crave such, recognize me. You _know_ me.”

Tony did. He’d hated it when Kuan-yun had taken Maria’s form, when Frigga had felt so _much_ like a mother—but _this_ woman, this being, was more than imitation. Some part of Maria Stark looked out those eyes—but looked out without judgment, without disappointment, with grief and yet no blame.

Natasha looked over at him and he found himself averting his eyes at her glance. Her expression was too open. Christ, he forgot sometimes how young she was—a lifetime of blood and death, but she was barely more than half his age, and youth was written all over her. Let her have this, whatever this was. This thing, where time could not touch them.

“I do,” she said, her voice quiet, but not as small as it had been. Young, but not vulnerable. She was protected, too. In one smooth movement she lifted the cup and drained it dry; Tony did look back at her, then, and when her eyes opened there was _something_ gone, something he hadn’t even noticed until it wasn’t there anymore—something that hadn’t been there when they’d left Earth, something fey and wild and broken: the Nidhogg, hiding just out of sight behind her eyes, in a form that even he could see, even if he hadn't realized it. “Oh,” she said, and it was a sound of surprised relief.

“Come and rest,” said Gaea, splitting again and coming to stand beside her; Gaea shepherded her away, to a different door beside the room, and through it.

“You have to be in my head,” said Tony, watching the Gaea that remained, and who was now seated opposite to him. He had to wet his lips to continue. No more Natasha to defer his decisions to, _christ what a coward_ “Or I would protest that. Splitting us up. This entire thing should be... creepy.”

“I’m not in your head. But although you don’t have a soul any longer, the... tethers, so to say, where it should be, recognize that none of this is actually happening: it’s not real, except in how it affects you. What you perceive is my protection, and that _does_ affect you.”

He eyed the cup of water remaining on the table. “That one for me?”

“If you wish it. Your soul is gone, and you are not vulnerable to the sight that so damaged your friend.” _Friend_. He supposed she was. “But there is another imbalance in your mind.”

“Loki’s program?” He twitched. His fingers tapped against the bench before he caught himself.

“You know it isn't,” Gaia said, and he couldn't even hate her for putting it so gently. She put both her hands on his shoulders and brushed them off, as if brushing lint from a suit-jacket. “He's laid tracker-spells to see where you are, nothing more, and now they are gone. Whether or not he tried more, he would not have succeeded in modifying Makluan links. _You_ are doing little better at modifying them yourself, there—little better, for at least you have the benefit of experiencing those links first-hand... but Maklu has had millennia to develop protections to keep their own children safe. You cannot fumble those and break them without millennia of experience of your own.”

“There’s an error _somewhere_ , I keep catching bugs—” He slammed his palms against the table, flat and shaking. “There’s something wrong.” And yes, he _knew_ part of it was in his head: the errors exponentiated when he got upset, he couldn’t deny it, but they had _started_ somewhere, and if only he could eliminate that problem –

“Just because you can no longer see the Nidhogg does not mean you are not vulnerable, in the way anyone is, to what you _have_ seen, Tony. Or done... or had done to you.”

His breath caught. He gasped in, sharp, too much. His lungs hurt. “That’s—that’s really just _it?_ That I just need _therapy—_ what, you’re telling me that, that PTSD is the reason pi sometimes comes out rational?”

“Your human body makes use of extremis, and is regulated by extremis, but you haven’t yet copied yourself entirely to it,” said Gaea. “When you fell through the internet, your mind was always at home in your own brain. You’ve discovered this yourself, in your attempt to copy yourself to a new body. You are differently made than your own creations, Tony. And your soul may be gone, but it is not destroyed and so neither are its tethers. With or without a soul, experiences such as you have had leave marks. In your case, it is not only emotionally but also physically, in errors within your biological neural processing.”

_the problem was me all along._

_not the sensory data. but how i read it?_

He scrubbed his hands over his face. “Fuck.”

“Medication, time, and normalcy can yet heal you.”

“Do I look like I have the fucking time?” he snarled, baring his teeth—as much rebellion as he’d ever shown to his own mother—as he was showing to something that was, in some way, his mother, his mother a part of her and she a part of what Maria had been—but he didn’t _feel_ sixteen all over again, he felt forty-four and terrified.

“No,” Gaea agreed. “This place I have set aside from you cannot last so long. I... we... are using too much of our power, keeping Thanos at bay. Hence the water.”

“What—what will it do?”

“Alleviate. Cure some of the damage. Not all. If you stayed, for a great time, and drank often of it... but sudden change is akin to destruction, and you do not have time.”

“One out of three,” he mumbled. Medication. At least he wouldn’t have to worry about missing a dose. Hopefully. “Permanent?”

“Yes.”

“You didn’t tell Natasha all this.”

“For her it works differently. The water flowed into the gaps that the Nidhogg ripped in her soul; it did not touch her mind.”

“Customized panacea.” It just looked like regular water. He looked at her, pleadingly. “Why do I trust you?” He shouldn’t.

“You know why,” she said gently. “You are not obligated to drink, Tony. It is offered. Nothing more.”

He did know, was the damned thing. He’d heard what she’d told Natasha and it made _sense_ somehow, damnit.

Tony wished he could have made some quip as he raised the cup to his lips, but nothing sprang to mind ahead of his panic. He downed it in one go, like Natasha had. It tasted just like water, but—better. It was that first sip of water after Afghanistan, when Rhodey had uncapped a water bottle and helped him drink it—he’d been more than a little out of it, by then—the water had been bathtub-warm and tasting of plastic, swallowing made his throat burn even worse, and it was the best damn drink he’d ever had, until now.

The panic became... less. Like it had moved into the next room, behind a door, maybe—there, but not _here_. Present, but not immediate. He shook his head. Tension unlocked in his muscles, tension he hadn’t even realized was there—he redirected the debugger to look into it. All of a sudden he was aware that he’d had a tension-headache for the last five hours, and had been ignoring it; he rubbed at his temples, and it began to fade.

The adrenaline faded, too. Shit, adrenaline levels were up _way_ too high—how long had he been running like this, and not noticed? He pitched forward as the chemical levels in his bloodstream went haywire—no, not haywire. Normalizing, after spending an ungodly period completely out of whack, and christ when was the last time he’d slept?

“You are safe here. Rest,” said Gaea, and he didn’t even bother worrying about her doing anything to him because he knew exactly why he was falling over, and she would never have hurt him anyway.

 _Loki_ _,_ he thought, with worry that wasn’t crushing. He could think it and set the debuggers to run on wide-scale, and a full defrag to run while he was out. Even as tired as he was, he could think, could multitask... could _decide,_ without looking to Natasha.

And then he was out.


	10. Knife and Hammer: 2.3

Unlike Tony, Jane wasn’t supported by half-alien nanites, but this didn’t seem to make much of a difference in the intensity of her focus. Long after Steve would have given up for neck-strain—even if she was short enough to walk beneath the roof, she still had to crane her head back to look up at it—she was still at it, her hands pressed against the silver surface, occasionally mumbling to herself. Steve, meanwhile, kept guard and tried not to fidget too much. He itched to go and scout the area around, but it wouldn’t be wise to split up, even if the place probably wasn’t like Maklu.

At long last, as the quality of light entering the telescope-pit began to grow redder and dimmer, she dropped her hands from the ceiling interface and stepped back for enough space to stretch—then immediately yelped, her hands flying to the back of her neck. “Oh, ow, ow!”

“Crick in your neck?”

“Crick from hell.” Jane rubbed her neck forcefully. “And I thought the university desks were ergonomic failures. Huh. Maybe these aliens are different.”

“I’ve seen some that are,” offered Steve, thinking of the Makluans. Although the Makluans, according to Thor, were shapeshifters; Steve had seen both humanoids and dragons and other, way weirder things among their number. But that still proved that they were out there.

“Yeah. Ow.” Jane rotated her head forward, then leaned over and touched her toes, grunting with the effort of stretching muscles that had frozen into place. “Ohh, I shouldn’t have stopped, I’m going to have a time getting going again.”

“Maybe you should take a break.”

“Haha. No. Loki’s going to be back soon.”

Probably. They had little time left. “Any luck with reprogramming it?”

“No.” Jane grimaced. “It’s just a telescope, Steve.”

Steve held up his hands. “Sorry. Past a certain point it’s all magic to me.”

“Sufficiently advanced, yep. We’ll catch up.” She stretched one last time, then raised her hands again, going back to it. But the look on her face was grim, not the intense curiosity she’d been settling into before. She was being driven to search through necessity, not a genuine love of the art. Or maybe she just needed to get her mind back into the zone for it.

A half-hour later, as the sky above grew _truly_ dark, Loki’s return split the air like a thunderclap, one not unlike the massive sound produced when Tony dumped out his subspace pocket. Steve clapped his hands over his ears as the mirrored surface proved that it could reflect sound just as well as light and the echoes temporarily overwhelmed everything else in this place. At least it didn’t crack, though Loki would have deserved it if it had.

‘And how have we been, children?’ Steve thought he saw Loki say. His lip-reading wasn’t the best. It looked bitchy enough to be something that Loki might say, though.

‘Ow,’ Jane mouthed, which was at least easier to figure out.

“Is it dark enough?” Steve asked, when he could hear himself think again.

Jane was still glaring at Loki, and didn’t seem to hear him—heck, maybe she didn’t. Steve’s hearing was more acute, and left him more vulnerable to ridiculously loud noises, but at least his eardrums healed over quicker.

He tried raising his voice. “IS IT DARK ENOUGH OUTSIDE YET?”

“Yes, yes, it’s fine.” Loki shot him an irritated glance, and then Jane one too, muttering, “Of course, she could not simply leave the telescope ready.” He strode over to where the roof flattened and raised his hands against it. Immediately the mirrored surface rippled and metal surged upward and over, spreading out above.

“If this is a device to avoid being seen, then somewhere in this device is a list of all places that must be checked,” said Loki, pressing his hands more closely against the mirrored surface as it finally ceased rippling. The glow of his magic spread about his hands, sinking into the roof. “All that is required is to find it... a spell for which I have been researching all day, and, at last, have returned with, triumphant.”

“Right, sure,” muttered Jane crossly. She had one arm wrapped around herself and looked tired and stiff, now that her concentration had been broken, but she left her other hand on the roof, looking up to check it frequently. “ _Oh_ , sure,” she said, a moment later, more acidly, but with a defeated note that let Steve know that Loki had found what he’d been looking for.

Steve stepped back, away from the middle of the telescope—although from what he remembered of his high-school physics classes, the entire lens was important to the telescope, so no matter where he stood he was probably interfering with it. But Jane didn’t seem in a hurry to get them out of the way, and she’d know and care, right? Although he wasn’t seeing the lens light up at all, either. Did that mean it didn’t reflect any light at _all_ , or that the light concentrated by the dish above was still too diffuse?

“A few minutes for it to view all aspects of the sky we wish to see,” murmured Loki.

“And then what?”

Loki raised an eyebrow at him.

“You said you needed a ‘paragon’ to crack this thing,” said Steve. He gestured at the telescope they were standing inside. “I’m not seeing that you need our help here.” For that matter, why hadn’t Loki managed to open the telescope earlier? It couldn’t have been that he was unwilling to swim down to the bottom of the pool... or had that been it? Had there been some secret test that Steve had been oblivious to?

“Oh, I’m sure we’ll see—ah,” said Loki, looking back to where his hand pressed against the interface. “Damn.”

“What?”

“Security protocols have locked us out.” Loki smiled in what was apparently an attempt to be reassuring, for once, as it had far less teeth than his other smiles. With only the light of the stars and his magic to go by, it still looked positively ghoulish. “Fortunately, when it comes to illusions and riddles, I’m very good.”

“Not that good,” said Jane, bringing her other hand up to press it against the ceiling as well. “It hasn’t locked _me_ out—it’s just you.” Then, snidely, “I wonder why it wouldn’t like you.”

Loki pulled his hands away, then put them back again. He frowned. “So it has. What— _ah_.” Was it Steve’s imagination, or did his eyes gleam brighter in the dim glow? “You do it, then.” He lifted his hands away and waved carelessly.

“What, you give up?”

“There’s little point in struggling against it. As you said, you’re not locked out.”

“Well—fine.” She glared back up at the interface.

The bowl moving above wasn’t really anything Steve could _hear_ , per se—even for him, it was at the lower range of his hearing. But something that massive being moved caused a vibration that he could feel resonating in his bones. In the darkness, from down here, he couldn’t tell if it was all moving as one piece, like some sort of oversized satellite dish, or if the quicksilver that comprised it was just flowing into a new position.

“Scans coming through,” said Jane, her eyes fixed upward. “Oh, wow. If I had a laptop, an adapter, _anything_...”

Loki’s eyes flashed with amusement in the darkness. This time Steve was sure they had actually flashed, or flared—that had been illumination.

“...that’s why it locked _you_ out, isn’t it?” Jane finished, pulling her hands down. Above them, the dish stilled.

“You are a paragon of learning, Lady Foster.”

“ _Dr._ Foster, thanks,” she snapped, her hands clenching into fists.

“Dr. Foster,” he amended smoothly. “Some of us have baser concerns—such as, oh, the salvation of the multiverse. Shall we go?”

Jane turned her head away sharply. Her hands were still clenched. After a moment, she tucked one away in the pocket of her coat, and reached up to tap twice at the ceiling with the other.

The effect was immediate; the sound, immense. Two straight cracks ran down the telescope lens, crossing in the middle, perfectly aligned with the corners of the inverted pyramid above. In the walls around them something massive groaned as ancient machinery came to life for the first time in an age, and the four segments of the lens began to tip downwards, tilting, opening to the below. Beneath Steve’s feet the glass, or whatever it was, turned suddenly slippery as it sloped. He swung his shield around as hard as he could, aiming the edge for the glass, but it bounced right off, completely failing to dig in. He began to slip. Jane had been further from the centre—she yelped, slapping her palms against the glass and trying to get traction just as Steve was, but it was just as useless.

“Loki!”

“I can’t!” Loki called back, a note of panic in his reply. There were flashes of green light, bursts of un-coordinated magic. Loki snapped his fingers, but nothing happened.

The lens segments tilted further and Steve slid faster. Before he could fall over the edge, he coiled his feet beneath him and pushed off and _up_ , leaping across the ever-widening gap to the segment that Jane was about to slip off of. His hand closed about her foot—and then they were both in free-fall, falling down through impenetrable darkness. The stars above, Loki’s magic light—both were gone, lost.

Jane screamed as they fell, and Steve grit his teeth to keep from doing the same. He couldn’t see the bottom, couldn’t see anything. He twisted over, putting himself between Jane and the bottom, and the shield below them both. If there _was_ a bottom to this pit, it was a futile gesture—they’d fallen too far already.

And then they hit... something. Something with enough force to make the edges of the shield dig into his body, and to squish Jane against him in turn, but no more than that. A moment later, and they fell into water.

It was deep water. It closed over his head—cold, and he was choking, drowning—he’d lost track of Jane—

The water fell away, knocking him down but leaving him in _air_ , blessed, blessed air. He rolled to hands and feet—wetly; there was still a good inch of water between him and the ground, or wherever this was—and hacked up a lungful of water, then just gasped for breath. After a few seconds, he remembered Jane and in the same instant realized she was next to him, also hacking up water. Loki, a dozen feet away, was doing the same—looking very mortal now, in the pale illumination coming up from beneath the floor.

“Oh god, let’s not do that again,” gasped Jane. “Ever.”

“With you there,” Steve said, and coughed some more.

“Where _are_ we?” she asked, starting to get up, and then—“Ohhhh.”

“Jane?”

“Stop moving,” she said, her voice hushed, “And look down. Properly.”

The water was still disturbed enough that nothing was really clear, but he could see ribbons of light through it—blues, mostly, edged with greens and purples. And they were moving. He’d thought that was just the water itself moving, but as the surface stilled, Steve could see that the lights were actually moving independently, curling about themselves... flowing. And beyond it... were those _stars?_

“The bottom of this forsaken world,” said Loki, voice rasping, as he climbed to his feet. He glanced down, and shuddered. “Looking out the other side.”

“The Temple of Uttermost Winds,” breathed Jane. “ _Oh_ my god. It’s _solar_ wind.”

“Not—quite,” said Loki. His voice broke in the middle, and he clapped a hand over his mouth, then removed it almost immediately. “Not quite. _Dr._ Foster. Those aren’t—those aren’t stars.”

She looked at him oddly. “What are they, then?”

“Realities,” said Loki, and he let out a small, hysterical giggle and immediately covered his mouth again. When he next spoke it was muffled. “And the wind is the Dragon’s Breath.”

“Tony told me about that,” said Steve. He didn’t add, _sort of_. No point complicating things, not with Loki suddenly _giggling_. Steve took a few slow steps to put himself in front of Jane, and with each step, the water swirled in against his boots, reminding him that, actually, it was damn cold. He’d need to talk to Tony about water proofing. No doubt it would be a lot easier to talk about than _this_ place. “The... framework of the universe, I thought he called it.”

“More like the space where the framework exists,” said Foster. “The gap, I mean. The framework exists within it—I mean, it’s all there in the math, in the physics, how our wormhole bridges work. But... wow. This is... an _amazing_ representation.” He could picture her expression from the awe in her voice.

Loki squeezed his eyes shut, bringing up his other hand, too—a child, hiding, terrified. There were small tremors in the water at his feet.

“Loki?” Steve asked. “Hey. Loki...”

“Wow. Okay. Uh. What’s, um, going on with him?”

“We should back off,” said Steve, suiting action to words and shepherding Jane behind him. He didn’t dare take his eyes off Loki, though, as he carefully stepped through the water, darting glances down to check if he was about to back off _of_ anything.

“Did he just—lose it?” hissed Jane, keeping her voice low.

Steve waited until they were a bit further away before he answered her, although he couldn’t be certain that they’d be out of Loki’s range of hearing. He didn’t actually want to let Loki out of his sightline—if Loki moved, Steve wanted to see him coming. Even if there was every chance that Loki could just use an illusion to fake it, and even if it was likely that he could overpower Steve no matter anyway, Steve would take whatever small chance he could get.

“You know how... Tony was crazy, right?”

“Darcy—Darcy thinks he’s still crazy.”

“I don’t know about that. I do know that he _was_ actually mentally ill, hearing... voices... this was, um, while he was working on extremis.”

“What, _seriously?_ ”

“Yes.” Steve glanced down at his feet and up again. Had Loki moved? No, he was still right there. Steve had caught sight of something else, though, a bright point that had been hidden beneath the swirling aurora, but was visible now that they’d moved to see it at an angle rather than looking straight down at it... which meant that it had to be a _lot_ closer than any of the stars, which hadn’t seemed to move at all. “What is that, down there?”

“Something shining brighter... a closer reality?” Jane theorized, and then he heard her shake her head, her coat ruffling at the motion. “No, wait, the zombie-fying nanovirus is because he was actually crazy? I thought it was the, the terrorists.”

“Yeah, that _was_ them. Um, but the mental illness was because of something that happened the first time he travelled between realities. He crossed, well, this place we’re standing over, and saw something he shouldn’t have.”

“So you’re saying SHIELD’s planning to turn its agents crazy.”

“No,” said Steve, exasperated. “That’s a different way to travel.” He sincerely hoped. “I’m saying whatever is below us is dangerous. I don’t think we should be looking at it.”

“Then why did you just ask me to _look down there!”_

“I meant directly! I don’t think we should look at it directly,” Steve backpedalled. “I think we’d know if it was affecting us, it sounded like it was pretty obvious. But I think _his_ problem is that he’s been through it.” He gestured toward Loki. “That looks kinda like a flashback.” Or just a general nervous melt-down—or maybe something far less human. Loki was, after all, an alien.

“Great,” Jane muttered. “Just great. Okay. Let me try... oh, cold, cold, cold,” she chanted, crouching down to stick her hands in the water, against the surface of the floor. “And... okay, yes, it works the same way it did above. And my hands are going numb.”

“Don’t put yourself at risk of frostbite.” Which reminded Steve that he needed to keep an eye on her for hypothermia. He was only mildly chilled, but he ran hot. Jane, on the other hand, was a heck of a lot smaller than him, and without the benefit of his metabolism.

“Ha, ha... okay. This is more straightforward.” She withdrew her hands, shaking them off and tucking them under her armpits, shivering violently as she rose. “Cold. Okay. I think I can modify the floor, a bit like the telescope. Make it thicker and raise us up again, or make it thinner, or make it go away.” She bit her lip. “And... I don’t think that _is_ a closer reality.”

“Why not?”

“It's _too_ much closer and brighter. The other points don't seem to shift at all when we do, but that one does—it's like comparing a comet to the backdrop of stars. Plus, we're still in a reality, here, and two realities being able to get so close like this without causing some sort of weird destabilizing effect seems unlikely. It _could_ be like a binary system, but those are hell on planets, and this place is pretty hospitable to human life. And finally—it's blue, shiny, and hidden beneath the telescope.”

“You think it’s the Gem?” Steve was doubtful. “He didn’t mention it would be shining like _that_.” The Soul Gem he’d seen hadn’t.

“Well... I guess you’re the one who’s seen one before. But it has to be something.”

“You’re probably right,” Steve murmured, frowning. Loki still hadn’t moved from his spot, but was still shaking like a leaf. He didn’t seem to be paying any attention to the conversation, or even be aware of Steve and Jane at all.

God above, but even Loki didn’t deserve that.

Probably.

“Right,” said Jane, following his gaze. “So we just need to somehow retrieve it, while not... turning into that. Okay. Easy.”

“Really?”

“No.” Jane shot him an exasperated look, and shivered harder. “Only the top of this platform extends—there’s no option to flip it. And that’s _not_ just a matter of reprogramming it. If I tried the entire thing would destabilize and lose phase coherency—not good.”

“Okay,” said Steve slowly. “What about... gravity?”

“Gravity? Ohh... you’re actually pretty clever—I mean, not that I thought—I didn’t think you were stupid, or anything, I just—that’s a good idea!”

“So it might work?” Steve asked, keeping the dryness from his voice with what was, he thought, rather admirable effort.

Jane crouched down again. “Yes, I think—I see your point, okay. We have artificial gravity here on this strip, and... _yes_ , that reverses on the other side. So... if there’s a hole in it, whoever walks through doesn’t _fall_ , they just flip over. I could maybe reduce the gravity, and then it would actually be possible to just jump up and grab it, maybe? Um, assuming the lack of atmosphere wasn’t fatal. Or the... not-there-ness of it. Although there’s gravity in it.” She frowned, rubbing her hands together to warm them. “It’s not just a wall, it exudes pretty complicated field on that side, too. It’s like it... pushes back the nothingness of it? But I don’t know what that would mean for _looking_ at it.”

“Okay.” Right. Tony had lived with this for six months, and made zombies—but his decline had been gradual, and controlled in its own way; if Steve just _told_ SHIELD, or told Jane to tell them, then his would be a whole lot less damaging. And, hell, maybe it _could_ be controlled with medications and therapy. He was insisting Tony go—he could take his own advice. “Okay. You need to build a wall, between you and it. Can you alter its shape that much?”

“Oh, sure. But, Steve—”

“Build a wall to protect yourself, then drop me through. Modify the gravity, I’ll grab it, let me back through, and that’ll be it—we’ll be good to return to the surface.”

“But—I can’t—you’ll go crazy!” Jane protested.

“Well, you can’t do it—you need to control the floor.”

“I can do that just fine on either side.” She uncrossed her arms to put them on her hips, drawing herself upward. It didn’t actually make her look any more imposing. “In fact, _you_ don’t have the vote here, since it’s _me_ who can do it.”

Her voice was rising—partly bluster, partly fear. Hell, she knew what she was not-quite-volunteering for.

“ _Dr._ Foster,” Steve held up a hand, “the fact of the matter is, we need you sane back on Earth a hell of a lot more than they need me. I’m just a soldier—they can afford to take me off-duty long enough to get my head put back together. If we’re going to fix, ah, other stuff, we need you.”

“That’s _bullshit_ ,” she snapped. “Bullshit. No. Okay. There has to be a way. Blindfolds, obviously, don’t work, or Tony wouldn’t have—but if we have—”

“From what I understand, it goes through all barriers, once you’re over there. One of the smartest races in the multiverse couldn’t come up with a way around it.” They’d brought in Tony, instead—and been stymied by him. “Doc, c’mon.”

Steve started walking back over to Loki, and Jane, refusing to be left behind, hurried after him. She was mumbling under her breath, and then, louder, “Absolutely not. I’m not going to send someone out to get their mind ripped apart, or whatever it is that this does. I’ll—rock-paper-scissors.”

Steve stopped, a few paces back from where they’d started. “What?”

“We’ll rock-paper-scissors for it,” said Jane, her fist held out in front of her. “Fair’s fair. Whoever wins gets to see the underside of the multiverse up close and personal.” There was a horridly cheerful expression on her face, a mask that did nothing to hide the fear in her eyes.

“Jane. You don’t want to do this.”

“Neither do you.”

“I know my duty.”

“So do I! This is the fate of the entire _Earth_ , and more, and—”

“And we need you as a _scientist_.” He gestured out at the starscape around them, and up, where far above, the segmented telescope lens loomed somewhere out of sight. “You figured this out in no time flat, and I still don’t have a clue what the heck you were even _looking_ at.”

“Well, no, it’s a neural feedback interface—”

“And I have only the vaguest idea what that is, but how many other scientists—even SHIELD scientists—could get it that fast? Tony says we owe you half the portal theory in the first place—”

If it came down to it, the things Steve knew about Tony... no, that wouldn’t happen. Maybe death wouldn’t stop a soul, or the Makluan mantra, but Steve wasn’t normal. They could stick him in deepfreeze long enough to work out a solution, if he became a risk.

“Yeah, but— _rock-paper-scissors!_ ” She was glaring at him, and shaking from more than just the cold. “Look, I am _not_ backing down on this, I am _not_ just letting you go off and nobly go crazy!”

Steve eyed her, marshalling arguments.

_Or..._

“Fine,” he grit out, clenching his own hand into a fist. “Fine. Rock—”

She joined him, pumping her fist up and down in the same manner, for “—paper, scissors,” but though he kept his eyes locked on hers, his focus was on her peripheral vision—on the muscles in her hand, so tightly clenched... clenched, and not moving as their hands came down for the last throw... halfway down and at the last moment before it would become suspicious, he flipped his palm open, faster-than-human reflexes making it like a spring releasing.

“Shit,” said Jane, looking at her rock to his paper. “But scissors is _always_ more likely to be chosen, it’s been shown...”

“I figured you’d think that,” Steve lied.

“But that’s cheating!”

“And what were you doing?” Steve shoved his shield onto his back—even if it made him feel vulnerable, not having it held ready when Loki was right _there_ , there was no way he wanted to lose his shield to the Void. “You lost fair and square. Wall first, then drop me through.”

“But—” Jane looked down, and after a visible struggle, stopped herself from protesting further. “Damn it. Don’t—just—hold on to yourself,” she said instead, the words coming out half-disjointed.

“I will. I’m ready.”

“Okay.” Jane took a deep breath and lowered herself to press her palms through the icy water again. “Okay. Be okay, okay?”

“I will.”

Jane scrunched her eyes closed, and a nearly invisible wall of glass—or whatever the floor actually was—rose up around Steve. When she opened her eyes and spoke again, he couldn’t hear her: it was sound-proof. He could read what she was saying though: 'Okay. On three. One. Two. _Three.'_

The floor beneath his feet wobbled, then vanished, and Steve flipped into a roll, tucking himself in tight. There was no good way to prepare to land; his inner sense of balance was gone, and their alien surroundings didn’t lend much to a visible sense, either. He peeked his eyes open for a moment, and saw Jane couched underneath the floor, upside down... then his feet hit something solid and he craned his head upward, opening his eyes long enough to get a glimpse of the shining stone far above.

Jane must have changed the gravity field at that moment, because his whole body at once felt lighter. He couldn’t see the blue Gem, but it had to be up there, right? Just past the aurora—the ‘dragon’s breath’. He didn’t see the dragon, not yet, but there was no point in sticking around to find out. He kicked off, and the low gravity took him further than it ever should have, sending him soaring up through a veil of blue light.

Not light.

_Worthy...?_

_Not our place. Not gods._

_...give up our trust, after all this time..._

_Far down here._

_Never found... until now..._

No dragon’s breath, nor solar wind, either. Steve breathed, the sudden whispers making him forget he had meant to hold his breath, and breathed in _thoughts_ —a multitude, the hopes and fears of an entire race— _hide us, don’t let Them see, far beneath the Earth, oh god, oh god, help us—_ they rose in a clamour and he knew that if he listened, he would be overwhelmed.

Steve coughed frantically, expelling them from his chest and his mind, and the Gem was right in front of his eyes. Past it his eyes met another’s, staring back at him from across the shining blue. He reached out, but couldn’t quite grasp the Gem in his fingers; it slipped through. An illusion.

_You braved madness to come here... not for yourself._

_Will you be leaving, Stranger?_

_Yes_ , Steve tried to say, but there wasn’t actually any air in this place: only thought.

_Then swear... that you will bury it behind you._

_...bury us..._

_I will,_ Steve promised, and his fist clenched around something hard. He fell.

The ground caught him and broke his fall gently, stretching beneath his weight and then dissolving. Gravity flipped over, and he fell back ‘up’, which was now down, and lay gasping on the floor in an inch of frigid water—an inch, even though the floor he was lying on was, he saw after a moment, three feet above where Jane’s feet were. He coughed, breathing out blue light, and frantically sucked in air—sucked in something _real_.

“Steve?” Jane asked frantically. “Steve? You okay?”

“M’okay,” he said, and coughed again.

“You’re, uh, breathing light, what is this stuff?”

“I got it,” he said, and opened his fingers. In his grasp, the Gem shone, but only gently. Its inner light was hidden. He gripped it tight again before he could lose it, and one glance across Jane showed him—

— _she was worried about him—_

— _this place was so cold and god, she wanted to go home—_

— _selfishly, she was also worried about herself, if he went insane—_

— _she felt guilty—_

— _so relieved, angry at her guilt, she had a right to safety—_

— _guiltier—_

— _the pursuit of knowledge: and look where that had landed Darcy—_

— _bystanders caught up, and wasn’t she supposed to be a bystander?—_

— _at this point she’d drink even Bruce’s godawful tea, at least it was hot—_

—Steve clapped his free hand over his eyes and forced himself to loosen his grip on the Gem. The flood of her thoughts cut off as he shoved them away—and then, for a moment, his finger was on the trigger, and if he pushed any harder he suddenly knew he’d be shoving thoughts _in_ instead. He fumbled the Gem and nearly dropped it.

“Steve! Are you okay?”

“Yeah,” he got out, voice rough. In his own head, he pictured his shield: himself behind it, and Jane firmly on the other side. _Keep your hands to yourself, Rogers. And your brain, too._ “Yeah, I—this is it, alright.”

“Oh. Uh.” Jane twitched nervously. “Uh, are you reading my thoughts?”

“Trying hard not to.” He opened his eyes, staring at the ground, then realized he could still see the light-beings past it, and shut his eyes again. “It wasn’t—I don’t know what that was, but I don’t think that was the Gap.”

“It wasn’t?” He could hear the curiosity in her voice, hear—nope, he wasn’t hearing that. He told himself so firmly, and managed to make it true after a second. “But the basic data here, what’s programmed into the floor, _it_ thinks it is.”

“The, um, the people who built this place, they’re still hiding.” Steve rubbed his forehead. “I think it was a test. When we go up... the telescope. Can you pull it down, permanently? The people here don’t want to be found. I promised.”

“I—well, okay, that’s creepy. Yeah, I _can_ , Steve, but...”

 _Scientists._ “I promised them.”

Jane sighed. “Yeah. Okay. But...”

He let himself wonder what the _but_ was long enough for it to become apparent that the answer wasn’t mysteriously appearing in his mind, courtesy of the Gem. _Good_. Warily, he risked a glance upward. She was regarding him with considerable concern, and no small amount of wariness of her own, but she looked reassured when he met her gaze and nodded. “But?” he prompted.

She tilted her head, her eyebrows raising meaningfully. Steve followed her glance... _ah_.

The Gem had thrown him more off-balance than he’d thought, if he’d forgotten _Loki_ standing there.

If it were anything like the soul gem he’d had, it would work on Loki, too. He could use it to find out whatever Loki was plotting, what tricks he had up his sleeve, what cruelty he intended towards Tony. Push hard enough... he could _stop_ Loki. Could he change him permanently?

Oh, God, was that his own thought? Or the Gem’s? Stephen Strange had warned him that the soul gem _liked_ stealing souls. Did the Mind Gem, bigger and nastier than a mirror gem, do the same with thoughts?

Steve shuddered, a body-wracking jolt that sent droplets of water flying off to disturb the not-quite-pond all around them. The water near Loki was already disturbed—Loki was still shaking, still with his hands over his face, hiding from something only he could see.

Looking at an Asgardian with the soul gem had been almost more than Steve’s mind had been able to bear. It had nearly brought him to his knees. If he tried doing the same with the Mind Gem, it could backfire badly. But... on the other hand, he couldn’t fight Loki off, physically. And he couldn’t just surrender the Gem. If it came down to it—

—he wouldn’t change his mind. _Couldn’t_. That would be too much of a violation, no matter who the victim was. But if it came down to holding Loki in place... that was something else. He still didn’t want to find out if it was doable.

“I mean,” said Jane, breaking the silence. “I. Um. I could bury him down here, with it. Or drop him through. Without gravity on that side.” She added this last in a rush, nearly choking on the words, like she was trying not to be sick.

 _Murder_ , she meant.

Worse than murder, if the place beyond—past the alien consciousnesses—was the Gap after all. Loki had fallen through once before, after all, like Tony had. If he hadn’t died then... if he could _survive_ it...

“No,” said Steve, finding his voice at last. “No. We’re better than that. And I have the Gem. We’ll be okay.”

“I hate him,” Jane mumbled. She sounded relieved, though.

Steve shook his head, and let that be his agreement. “You can raise us up—now?”

“Yeah.” Jane put her hands to the side of one of the walls she’d raised. The side itself was covered in an inch of water, which in defiance of whatever gravity existed on _this_ side, didn’t flow at all. “Yeah. Okay, keep your balance. This might be rocky.”

No sooner had she finished speaking than the floor shot up beneath them, so fast that they both slipped, the light from below vanishing beneath God knew how much glass. Jane yelped as she fell over, fumbling about—the only glow now was from the Gem, too dim for a normal human to see by, and in the confusion and the dark she cried, “No, _stop!”_

They stopped, so abruptly that they were in effect tossed up into the air. Steve tucked in his legs and managed to find his balance so that when he came back down, he landed on his feet and stayed there. Jane wasn’t so lucky; she hit with a splash and a cry of pain.

“You okay?” he asked, leaning over despite his inclination to _stay away_ for so long as he held the Gem—going closer was dangerous...

“Ow, funnybone,” she gritted out. “I’m—I’m fine...”

“This is very wet,” said Loki’s voice, and there was a slight hissing noise as one of his lights bloomed into existence. Steve looked over at him to see steam rising off of him in a cloud: he’d dried off his clothes with magic, apparently.

He didn’t bother offering to do the same for Steve or Jane. Instead the focus of Loki’s gaze constricted, the full force of his attention snapping onto Steve and what Steve was holding. Steve hadn’t risked putting the Gem in a pocket, not when Loki was right _there_. But maybe he should have, because Loki could sense, it, somehow—

Steve’s control must have slipped; he felt Loki’s intent a moment before it crystallized, a surprisingly harmless spell, one intended to simply pluck the Gem from his hand. His grip tightened, although he knew—in the same way he knew what Loki was casting—that it wouldn’t do any good against this _particular_ spell. But his increased awareness of the Gem was like opening a door, and he wasn’t fighting against seeing Loki as he was against seeing Jane—

— _all of them would pay in the end and all of them in the end and all pay_

— _mirrors shatter shatterglass falling falling he think of no it wouldn’t_

— _whisper and the dark came down and twisted spider_

— _going dying_

— _salvation there point of light light light not-dark not-shadow shade silhouette mistaken—_

— _should have should have plan no where had it gone—_

“Don’t,” Steve told him. It was not just a word.

Loki froze in his tracks, eyes wide—and then furious, as Steve thought desperately of his shield again, raising it on his arm in unintended mimicry. He didn’t _want_ to see in Loki’s head. Loki’s mind was like Tony’s had been, that brief time Anthony had shown him, but somehow even worse—Tony had been lost in despair, fear, and confusion, but with the Gem Steve could see that Loki’s mind was _scattered_ , and whether it was the norm for Asgardians or not, he couldn’t tell and didn’t want to. If he wandered in there, he would get lost.

Loki glared at him, and Steve was grateful, because it meant he was safely inside his own head instead—safe, compared to trying to change that monstrous, ruined landscape. One command to freeze Loki, quick and dirty, and get out, stay _out_. Don’t try to change anything. Don’t get _trapped_.

“Ah,” said Loki.

“Looks like you get to keep your word about seeing it safely into someone else’s hand,” said Steve firmly.

“You can’t make full use of it on its own, Captain. No mortal could, even with its companions.” Loki’s expression gave nothing away, but enough still slipped through the Gem for Steve to feel the lie, hear the desperate whispers of Loki’s barest, nearest thoughts, all focused on possession of the Gem.

Well, even in the first place he hadn’t thought Loki was telling the truth about being willing to give it up.

“Jane,” Steve said, not taking his eyes off of Loki, “can you get us the rest of the way up?”

“Um.” It came out rather squeaky; Jane cleared her throat. “Uh. Yeah. I’ll try to make it slower this time.”

He heard splashing as she knelt, and then the floor moved again, but this time it was more like an elevator than a sling-shot. He barely jolted, sliding one foot only a half-inch before he was balanced again. All the while, Loki didn’t stop looking between him and between the Gem in his hand with a hunger that wasn’t present on his face, but entirely in his thoughts...

Steve thought harder about his shield, until the sense of him dimmed to the barest whisper—and then he didn’t dare block Loki out any further.

“When we get to the surface,” he said, keeping his voice controlled, “Jane’s going to collapse the mirror in. Then you’re going to bring us back to Earth, exactly where we left from. If you try to do anything else, I’ll know, and I’ll stop you.”

“You could simply do it _through_ me,” Loki said. No physical sign betrayed his nervousness.

“Mortal,” Steve tossed back at him.

“Idealist,” Loki sneered.

“Please shut up,” said Jane, and since she was in charge of the ride, they did.

Stars appeared through a hole overhead—suddenly enough that there had to have been something in the way for them not to have been visible earlier. The telescope lens, perhaps, or some other part of the apparatus. They rose toward it steadily, the temperature dropping in a way that would have been nearly unnoticeable if Steve hadn’t been soaked through. Loki’s light started casting reflections off of the approaching ceiling—and then they were up, through, and standing in the middle of the massive mirrored bowl. It was wobbling.

“O-kay,” said Jane. “This is... we should get out of the middle, first.”

Steve nodded to Loki. “Lead the way.”

Loki did, not without sketching a mocking bow. Steve could hear the furious rage behind it, a snarl not unlike the scream of a thwarted toddler—but toddlers wouldn’t think of stars like broken glass, would they? Steve shuddered and forced himself to pull back, again. Loki’s mind was like quicksand—too easy to sink in without noticing, and hard to keep afloat.

One side of the mirrored bowl drooped in front of them, and then, like taffy stretched too far in the sun, slowly fell apart, creating a clear space they could walk through. They made their way up the slimy steps, out past the—

Movement. Loki whirled, spells turning to defence, and Steve raised his shield—blocking one blow, an attack out of the darkness from a mind he couldn’t sense even with the Gem, and then _pain_ —something, faster than he’d been able to catch, smashed into his other side, bones in his arm snapping and _the Gem oh god_ —

He didn’t know what had hit him. Two forms loomed out of nowhere, shaped—barely—like humans but made only of blank stone. Jane was screaming; around them, the bowl continued its collapse, casting reflections everywhere, two of Loki, one distended horribly—

“STOP!”

Their attackers froze at Loki’s shout. Steve, in the middle of ducking under a blow, finished his roll and wrenched himself to his feet. He couldn’t feel his hand, which meant his arm was probably going to hurt like a son-of-a-gun as soon as the adrenaline wore off and the pain kicked in. “Jane! You okay?” he called.

“ _Down,_ ” hissed Loki, gleefully, and Steve crashed to the ground.

He should get up, back on his feet.

The thought didn’t quite seem to make sense.

“You really should have looked further,” came Loki’s voice, amused.

Steve thought, _Roll over_. He rolled over, and looked up at Loki. The green spell-light was gone; the only illumination other than the stars was the gentle blue glow of the Mind Gem, held lightly between Loki’s outstretched thumb and fore-finger.

“Looking at you now,” said Loki, “I think, perhaps, I _was_ mistaken. With this Gem... this true version, not some paltry reflection... even a mortal would be able to overcome their own limits. It’s one of the keystones of creation, after all.”

Steve didn’t say anything.

“But of course you wouldn’t look further than my surface thoughts. That would be a violation. Or might have you violated. And so it all comes out as it was meant to in the end. I may not have been able to break into your mind so easily, Captain... but did it not occur to you that I could modify my _own_ memories? You see.”

He gestured. Steve looked over to where he pointed. The two stones that had framed the ruined Temple were gone. They had been moved and distorted. He recognized them now. They had been enchanted to wait for him to return with the Mind Gem and then attack him. He knew this the same way he’d known to roll over and look up at Loki, the same way that the tiny portion of him screaming in horror knew that it would have been silenced except for Loki _wanting_ it there. The bastard enjoyed having some portion of Steve realize what was happening, even as every other thought fell to Loki’s control.

“A simple enough preparation: mindless automatons, to spring a trap on someone who would be able to sense any _mind_ about to act against him. And then I merely had to bury my own memories of setting the spell,” Loki said aloud. “If there had been any risk that you would have _looked_ , it wouldn’t have been so easy—the Mind Gem can break any such spell I could cast, of course. But you’d never look. And now that _I_ have the Mind Gem...”

Steve sat up, and got to his feet. He stood still.

Loki leaned over to whisper in his ear. “Now _you_ can’t hide anything from _me_.”

Steve thought of the phrase that Tripitaka had chanted to control Tony.

“Oho, so that’s what had him so worried. I had wondered, but you know, total panic makes almost as marvellous a defence as your shield. This will be _most_ useful. You see, despite the encouragement you should have been, he hasn't yet done as I'd asked. But now—” Loki paused, one long finger raised in the air. “I think I'll have you encourage him _yourself_.”

Syllables rolled off Steve's tongue, alien and nonsensical. He spoke without pause for breath, until he was wheezing, and then he stopped.

“Excellent. How many other ways can you be of use, Captain?”

Steve thought of SHIELD’s base. Steve thought of the personnel there. Steve thought—

“—something a bit deeper. When the time is right...”

Steve agreed with the certainty that settled in his gut.

“...but I’ll be merciful. Until then— _forget_.”

Steve forgot.


	11. Knife and Hammer: 2.4

Tony opened his eyes, and knew exactly who he was, where he was, and what he was doing there. The debugger—never far from the front of his thoughts, these days—was silent. The last error had been cleared four hours prior, and an hour ago it had flipped into stand-by.

He sat up slowly, half-expecting a cascade of sensor errors, for the room to invert, or the colours to shift off his visible spectrum, or garbage sounds and smells to assault his brain. But nothing happened. The room—small, one single-sized bed, but it was possibly the most comfortable bed he’d ever slept on in his entire life—was rather boring, but the walls and corners and ceiling all made sense. The floor was where it was supposed to be. His vision wasn’t pixelating.

His hands were in his lap. He brought them up to eye-level. No tremors, no muscle twitches. No betraying data. Very deliberately, he thought, _Loki_ _._

There was a sour twist of fear in his stomach, and he clenched his hands into fists, tight enough that his worn-down nails bit into his palms. Loki was out there—Loki, _christ_ and he’d grabbed Steve. Loki, who had more power than any sane person would want in the hands of such a... genocidal maniac wasn’t a strong enough term. Accomplished nihilist?

Loki, who was going to shit his pants when he realized what, exactly, Tony was keeping in _his_ back pocket.

“Yeah,” Tony murmured. His voice was rough around the edges. He swallowed, triggered subroutines for the appropriate amount of saliva, recoded them so that he wouldn’t have to consciously think about it ever again, and tried a second time. “Yeah. Okay. I can work with this.”

Fear sung along his nerves, compelling and adrenaline-inducing. Not swamping; not abyssal.

First things first: he needed to find Natasha. Then he needed to talk to Gaea. If she was willing to point them in Steve’s direction—great. If not... if _not_ , then he still owed her... a lot. More than that. Loki had already handed over the keys to his own downfall, and now Tony could _see_ it.

_If you’re optimistic about it. And if you forget about the other accomplished nihilist running loose, the one who ganked the Living Tribunal._

He ruthlessly suppressed the thought, and then spent a moment enjoying his success at having done so.

As he swung his feet out of bed, he noticed they were bare. He was still wearing some clothing, a tank-top and loose pants, but the rest of the nanites had turned into part of the very cuddly blanket. Tony reclaimed them and they flowed over his skin, down to form boots, up to turn into a proper shirt, and a jacket because even if it was cosy in here they _were_ in a cave.

The whole place was heavily shielded; a pleasant white noise hummed along in the back of his thoughts. It was unlike the Raft or the bowels of the NYHQ, where the shielding had been distance and empty silence. When he paid attention to it for a second, pausing with his hand resting against the door—there was no handle, but there was also no lock and it wasn’t sealed around the edges; the door was visibly just ‘push to open’—he thought he might have found the hum intimidating in its own way, if it hadn’t also been immediately obvious, in the same manner by which all things about Gaea were obvious, that this was part of her protection of him.

A tiny, childish part of him bristled at the need to be protected. An equally childish part of him wanted to curl up and drift in it. _Whatever._ Both impulses could be ignored. He was protected here. It was a fact.

Tony pushed the door open, revealing the room with the table and benches and sink. None of the furniture had mysteriously disappeared since he’d conked out, and no more had been added. Gaea wasn’t in there, but Natasha was, looking relaxed and almost rueful as she sipped at a mug of hot chocolate. High-quality hot chocolate. A second mug was set out on the other side of the table, but it was empty.

“Join me,” she invited, when he paused.

There was this nagging sense that he owed her an apology. Tony slid onto the bench and over to the empty mug. Was she making a point?

“Fun trick this place has—pick it up and think what you want to drink,” Natasha advised.

 _Scotch_ _,_ he thought, raising the mug to his lips—and, sure enough. He whistled through wetted lips, the quality of it lingering on his tongue. But ethanol was a poison, and the nanites would just purge it from his bloodstream, unless he bothered to prevent them. _Coffee, then._ Not that caffeine couldn’t be toxic, in its own way and in sufficient quantity, but the guards were set a lot higher for it.

“So we lost... Rudolph’s brother.” _Wait a minute._ There was no need to avoid names anymore, even if he hadn't been pretty sure the shielding on this place would cover that, too. Foster—before he’d melted down on her yesterday, and Jesus Christ that was embarrassing—had tried to literally hand him the solution, and all that remained was to implement it. Tony set to work on reprogramming the nanites.

“Uh-huh,” agreed Natasha. She smiled. Did Tony’s eyes deceive him, or was there some regret in there? “But I think he’ll be fine. You know, I’ve been sitting here working my way through teas and trying to figure out how to report all this, and I’ve got nothing.”

He knew exactly what she meant. The humming protection all around them... the damn _familiarity_ of it. It should have been imposition, but it wasn’t. Yesterday, his brain had been out of whack, tripped out on fear, but when he’d come face to face with the Lady Gaea he’d still _known_. He’d trusted her, like he would have trusted his own mother. He still trusted her.

“Maybe leave out the part about the mind-altering drinks.”

“Sure, _maybe_.” She frowned. “Our missing companion could be a problem. If he saw what I saw—” She shook her head. “It’s disturbing. In the Gap, that _thing_... it shouldn’t exist. I keep thinking it can’t.”

He remembered it being tempting, during those months when he’d been going insane, to dwell upon the memories—memories he no longer had, of course. Something about train-wreck syndrome, maybe. Maybe once the mind degenerated enough, it sought out more madness, realizing that sanity wasn’t the answer... and he was getting way too philosophical about this. _Time for a topic change._ “Okay. Try this.”

Nanites rolled down his arm, configuring as they collected, until he had enough that he could plunk a replica of Foster’s device on the centre of the table. It was sleeker than the prototype she’d shown him, of course. Nanites made everything easier, and there was no point in shoddy construction. “Thor, Thor, such a bore,” Tony chanted, and then made a face because maybe that was a bit kindergarten. “He can’t hear me. We’re good.”

Natasha’s eyebrows lifted in surprise. “You’re sure it works?”

“Not my idea. Foster’s.”

“Hmm.” She leaned in. “You’ve tested it?”

“Testing it right now.” The dampening effect was, as a matter of fact, working fine, according to his gloriously well-behaved sensor arrays. “She worked out how they do it ages ago, this is the countermeasure.”

“Could _we?_ ”

“No. Humans aren’t, eh, dimensionally conscious enough.” He made a face. “What, peering through a reality-window isn’t enough for you?”

“Spy,” she reminded him. “Remind me to thank Foster for the new gadget. It’s impressive.”

When he narrowed his eyes at her, she just smirked. He turned it into an eye-roll instead and took a fortifying gulp of coffee—hot, black, bitter, just the way he liked it. He swallowed and cleared his throat. “Sure. Well. Options from here.”

“Gaea can probably get us home.” Would, too.

“Yeah. Or I can.” A corner of his mouth ticked down at that. Idiot. Panic had made him stupid. He didn’t know where this Earth was within its reality, exactly, but he knew they were in the Prime reality and he knew how the Prime reality related to theirs. From all his attempts to get into Asgard-Prime, he was familiar enough with the shape of this set of worlds that he could figure out their current location with some work and the Gap. It would take a bit of trial-and-error, but he could reorient.

“Not a mission success, though.”

“No.”

“You said options, plural.”

Tony grimaced again. “We could ask Gaea to give us directions to Steve and Foster. Depending on how we put it... eh, you might be able to convince her. I doubt I’d have much luck.”

“You want to kill Loki too badly,” and, well, fair enough.

“Uh-huh.”

“Third option, then.” Natasha leaned forward, studying him. “Get Hel to agree.”

Hel clearly knew more than she had said; Tony had picked up on that even through the massive brain-whiting panic attack. Getting it out of her was another matter. On the other hand, he didn't think that was what Natasha was driving at. “Possibly,” Tony said reluctantly.

“What’s this favour she thinks you owe her?”

“Two possible explanations on that. One, she’s lying. It wouldn’t be the first time.”

“Oh?”

“I’ve... met another version of her.”

“In the universe Loki came from?” She wasn’t surprised, not that she’d look it if she was, but Tony hadn’t expected her to be. Steve had mentioned it in his report.

“Yeah. She’s not half-bad at lying.”

“But I’m very good at discerning lies. Give me some credit, Tony.”

Right. “Second option, it could be another version of me.”

“Tony, I did _read_ Steve’s report. Time travel, right?”

“Could be. Might not be.”

“You definitely think it is.” She sat back, lifting her mug to hide her lower face, peering speculatively at him. “Why?”

“In the Raft—” The sentence ended before its time as fear rose in his throat—the memory of terror, and then, even more absurd, fear of the feeling itself. He was going to lose it again, he was— _I am_ not _, stop being an idiot._ He got a rein on the panic, and whatever had been in Gaea’s miracle drink was certainly worth the price, because nothing happened to his sensor modules. “He wanted my help.”

“And you refused. The tape didn’t sound like you gave him a chance to get around to specifying what for.”

Admission of oversight on her part—apology? Outreach? Shit, she’d been reaching out the whole damn month, hadn’t she? _Fear_ had said it was too close to her tactics to make people underestimate her, but... that wasn’t right. She didn’t _admit_ it, then, to her targets. She’d walk up unarmoured with a smile, and they’d see the lack of armour and ignore the smile, every warning that she gave off being read as a bluff instead. But she’d flat-out _told_ him.

Tit for tat. “He left something in my head, let it specify later—Gaea says it’s gone.”

“Tony...” It was half a growl.

“I know, I _know_.” _Apology. Right._ “I—look, I’m sorry, I’ve been unable to think straight for the past—while—“

“Yeah, I noticed! But any of us would have _helped_ ,” she said, looking, of all things, hurt. Real hurt—there was no uncertainty in it, no lure. “Would you accept help now?”

Tony swallowed. “I don’t know if you can help. It’s not... I told Steve...”

“What, mortals up against gods and monsters? SHIELD’s been doing pretty okay.”

“I know,” and, _Fine. The point’s been made._ SHIELD had been doing _terribly_ —but when he’d climbed on board, instead of keeping them in the dark... when the others had been there to keep out the _need_ to keep SHIELD in the dark... SHIELD had figured out the Thanos-detector before him, had contained extremis, was working with Bruce and treating him fairly. “He wanted me to find something for him. Called the Stone of Time.”

There was a pause while Natasha sipped something that smelled like raspberries, now. “I can see why you think it’s time-travel, then.”

“Uh-huh.”

“You know where it is.”

“Uh-huh,” Tony said again, with even less enthusiasm.

“The same thing as the Window Steve mentioned?” She didn’t wait for him to answer; it was probably obvious in his expression. “Or something related to it. Hm. Steve made it sound like you’d have jumped at the chance of it.”

“Aside from it being a _trap_.”

“No... you’ve changed your mind.”

She’d been admitting her weaknesses to him for weeks, which was not a ploy she could have _enjoyed._ But one he’d made necessary. _Quid pro pro._ “I don’t have enough of a grip on the math of it. Do you—yeah, you know. Math that _I_ can’t get a handle on—”

“You deal with brand new science all the time.”

“And look where that got me. If somebody _else_ did the math—but even the Makluans didn’t understand this thing, and I had to _try_ but I—I don’t know if—” He couldn’t make himself finish the sentence aloud, and this time it wasn’t panic that made it impossible, but the bitter tang of guilt.

He’d had to try to save the millions he’d killed, but he’d never really run the math.

 _I was lying to myself because I wanted it to be true. I didn’t really_ know. There had been no way for him to have known. He hadn’t had the data. He still didn’t.

“I get it,” she agreed. “And I get why Steve didn’t.”

“Doesn’t mean he’s wrong,” said Tony, staring at the table.

“So. If you find it, will you use it?”

“I—” Tony stopped. _I don’t know._

Natasha tilted her head in resigned acknowledgement—accept, dismiss, and move on. “Fine. If Loki wants it then it shouldn’t be left lying around anyway.”

“Yeah.” It was hard to make that more than a bare mumble.

_Coward_.

_...shut the hell up and start_ thinking _, then._ Hadn’t he wasted enough time already?

“Problem is, last time I saw it, it very thoroughly broke,” Tony said, eliding everything else that had happened. No point in dwelling on it. “Given that Loki asked _me_ , of all people, to go and get it, I have a pretty good idea of where it is, but when I say ‘broke’, I mean disintegrated. Atomized. Possibly more than that, my sensors weren’t... great, just then. So, _where_ it is, yes, that I know. But picking up the atomized bits of a ten tonne rock that have been scattered across the universe is gonna take a while. And then putting it back together...” He breathed out, puffing his cheeks out with his sigh. “He’ll spring his trap first. Loki’s got to have a better idea of how to fix it than I do, and until it _is_ put back together, it’s safest from _him_ in pieces, where he can’t get to it.”

“But.”

“Yeah. ‘But’.”

They were interrupted by the main door into the room swinging open. Beyond it stood two presences—Tony could almost get a sense of them as actual _presences_ , past all the white-space noise that was the gentle, nigh-infinite barrier of Gaea’s will. One of them, they’d seen yesterday—or whatever passed for yesterday in this place: the malevolently cloaked and cowled figure of Chthon. The other was feminine, vaguely, and was also cloaked and cowled, but something of her face was visible, as were the tresses of her hair, curling out from beneath her hood. Blue hair. And green skin.

Reflexes had Tony on his feet already, but Natasha hadn’t moved. _Better control of reflexes. Right._

“Peace, protectorate,” said the unknown lady, entering and stepping away from Chthon immediately, as if she found him distasteful. That gave her points... a bare minimum of points: it was the lowest possible bar to clear. Also, _protectorate?_

_Of Gaea? Fair point._

“Who are you?” Natasha asked coolly. She hadn’t even put down her cup of... vanilla cinnamon, now. Slowly, Tony stepped around the table so that he’d be on the same side as her, across from the two gods. Not that it would do them any good, if Gaea’s protection dropped and the new lady proved as malevolent as Chthon felt—either they’d be annihilated, or... well, they’d be annihilated.

“Oshtur,” she introduced herself. “Ma’at. Founder of the Vishanti, although you do not know of us on your world. You have already met my brother.”

Unseen eyes glanced over them. _Yeah, and he’d love a chance to meet us without your other relative watching._ Was Gaea a member of their ‘Pantheon’ as well? Mythologies that had ‘elder’ gods, precursors, tended to be full of familial relationships and no small amount of incest. There was a lovely thought.

“Egyptian,” Tony noted.

“In my widest-known form. I had been gone for a very long time, but this crisis gave me cause to return, at long last, even at risk of the balance our sister maintains.”

“And your return shall be celebrated,” said Chthon, breaking his silence at last. Somewhere, a very far ways away, an ocean of black sludge pounded against a cliff-side wall. The wall would fall, eventually...

Oshtur shot her brother a quelling look. “Enough. Mortal, we have decided to indulge little Loki in this matter. To a point. The Gems he seeks are useless to us; we precede their current structure and may not use them. Nor will they be effective against Thanos; they are not capable of collapsing this Dominion—this _cluster,_ as you call it—and he could be slain by nothing less. But that does not mean that the danger of them should not be recognized. Loki is not worthy to wield them. No lesser god is, nor any mortal. But given your unique theosophistical circumstances, in time you may come to understand what must be done with them.”

 _Is that actually a roundabout offer of help?_ Tony glanced at Natasha, but her face was impassive. If she had a damn clue about what sort of assistance they were offering, she wasn’t showing it. It couldn’t be straightforward.

“Enough,” said Chthon. Disdain oozed. “We are not here to converse.” From somewhere, he plucked a—Tony squinted. It looked like a point of blackness. But... it was a point. Sort of. Not merely a very small dot, but a... one-dimensional point, except it wasn’t even that. _How am I seeing a point?_

Still seated, Natasha twitched, squinting more than Tony was and then quickly giving it up to look away entirely. She raised her mug to cover her gaze, although her expression showed only discomfort, not a glimpse of insanity.

_Theosophistical circumstances?_

The point hung in the air when Chthon released it, a sizeless impossibility. Oshtur beckoned him forward, and she, too, had a point captured between thumb and forefinger. “Hold out your hand, Stark.”

Extremis formed a gauntlet on his left hand, pulling away from the back of his jacket. For the full armour he’d need to dip into the subspace pocket. Nanites hardened into a helmet, and half a chest-plate. It would do. No point offending them. Gingerly, he held his hand underneath the point.

“Mortal arrogance. There is nothing you could muster against us,” hissed Chthon, turning and stalking for the door—but not out. He paused in the doorway. “Uphold your part, bitch.”

_Classy._

Oshtur gave no sign it bothered her, and Tony didn’t let himself twitch. She moved her own point to overlap Chthon’s—two points, overlapping at the same point in space, the _same_ point—and neither was a point anymore, but one single, glittering... not-amethyst: the crystalline shape was all wrong. But the hue was similar, colouring the power that glowed from within, or maybe it was the other way around.

Oshtur dropped her hand away. Was that reluctance? Tony snagged the stone out of the air before she could change her mind. Tactile sensors told him that the stone was just as smoothly rounded as it looked— _definitely not amethyst_ —and faintly warm.

“The Stone of Space. Use it as it is meant to be used,” said Oshtur, and then she, too, turned on her heel and headed for the door. Chthon was already stalking out ahead of her.

Even after the wooden door shut behind them again, Tony remained still a moment longer. Oshtur and Chthon—whatever they were, ‘siblings’ of Gaea or not—could split themselves off into bits and pieces. Could they, would they, leave bits of themselves behind without him noticing? Gaea’s protection wrapped around them still, but even if the gods considered mortals beneath their notice, that didn’t mean they wouldn’t try to use them as pawns. That whole exchange had had _power struggle_ written all over it.

“Stone of Space,” said Natasha. “Like the Stone of Time, I’m guessing.”

“More like Gem,” Tony muttered, letting armour turn back into normal-looking clothes. The gauntlet remained. “Son of a—” His brain stumbled over the word _bitch_. Chthon was not so very far away, probably just outside that door. “It’s part of a set.”

“Time, space—” She left it hanging for him to fill in.

“Soul. Maybe more.”

“That wasn’t in Steve’s report.”

“Steve sometimes leaves things out, surprise,” he muttered, earning an amused snort. He stepped over the bench and sat down heavily, opening his hand again to look at it. Natasha looked, too—he twitched, ready to close his hand again, even though that had never worked against the Nidhogg. The Gem didn’t seem to harm her, though. She just eyed it with interest, then looked up and caught his own eyes.

“Soul. Then it’s not just... physical matter.”

“You were going to say _science_ ,” he accused.

“If the shoe fits—”

“The foot is ‘advanced alien technology’.”

“Can you find Steve and Foster with it?”

He curled his fingers around the stone. “I don’t have the first idea how to use it. Although, from what Steve said...” Natasha’s eyes narrowed—she _wanted_ that story, and she was letting him know it, but she didn’t pursue it for now—“it should be pretty self-instructive.” He hesitated. “Maybe you should do it.”

“They gave it to you. Loki’s focused on you. I think you need it more.”

“Reassuring, thanks.”

“Try it.”

Hesitance, again. But there was no real use to waiting. It wasn’t like there was a lab or a containment box that he could put this in to test it safely. Hell, he was wearing the gauntlet as if that would protect him from it, but that wasn’t really true, was it? It wasn’t explosive. He hoped it wasn’t explosive. Even if it _was_ explosive, the threat of its power was... different.

If the Time Gem was related to the Window of Time, and they all worked in the same general manner, then all he should have to do was concentrate on it. _Steve. Foster. Where are they?_

It wasn’t like using the Window.

His awareness of the space around him rolled out, the matter and energy occupying it slamming into his brain, cramming in data as it grew in a bubble, and the energy signatures here were alien to him, and too high, or too minute, taking up ever-increasing amounts of memory. _Slower_ , he tried to think, but that didn’t help when none of it was going _away_ —he tried clearing memory and whatever was deleted flooded back in—

Warning: memory low

_STOP_

Data cleared. Memory cleared. Enough space freed up that he could process some of what he’d just seen—putting it together, making links so that it wasn’t just a brain-breaking amount of discrete data points, but a picture of what the world around him looked like.

Answer: he was now lying on the floor. The bench and table had been shoved away from him to make room, and Natasha’s jacket had been pillowed up under his head.

“Shit,” he said aloud.

“That didn’t look like it went so well,” said Natasha, moving into his direct, biological-eyes field-of-view. “You okay?”

“Peachy.” He sat up and tossed her jacket back to her; she pulled it on and shook her hair out as he climbed to his feet. “Too much data. The Window... damn.”

“What?”

“The Makluans didn’t know what the Window was _for_ —they didn’t really have any idea how it worked. I _thought_ it housed the Time Gem, but it must also have... harnessed it, somehow, made it possible to use, unless that was down to location...”

In the nothingness that was the Gap, how many data-points would the Space Gem be able to feed him?

“Do you think you can control it on your own?”

_Yes. No._

“Not like this,” he admitted. “If it’s even possible to duplicate the Window... honestly, I’ve got no clue.”

“Then we’re back to our earlier list of options.”

Their earlier list of options essentially boiled down to ‘go back to all the Plan As, and ask more convincingly this time’. Not the best ideas they’d ever had. Unless they wanted to ask Oshtur instead—Chthon was right out—or someone else from that group down in the other cave... _Or you could try to figure out the Gem for more than a minute._

Right. How to do that? Limit it. The Gem had to be enhancing his ability to comprehend the information it fed him—he wasn’t sure exactly what range he’d gotten out to on his first attempt, but he had junk data left over with readings from at least five metres away, and considering how comprehensive the data sweep had been, the Gem must have improved his memory storage by several orders of magnitude. _How_ it did so... was another problem.

He tried thinking about a point in the air in front of him. The Gem obligingly filled in the data—a picture of the universe on the infinitesimal scale. There were physicists and chemists who would kill to be wearing his shoes right now. If he tried to limit the sampling... he thought about boundary conditions, space within and space without, and limited feedback loops, sampling. If he pictured a larger space, he didn’t need to know what every point in it was doing—treat the entire thing as a point and register or manipulate it on that regard.

Gradually, he expanded his awareness until he had a sphere of air right over his palm. There were enough points pinging from it that he could have turned off all of his external sensors and still been able to map the pressure and temperature differentials within it. And if he could _move_ it...

There was a small pop, and Tony’s awareness of it was shifted one metre left.

“Tony?”

“That wasn’t on purpose,” he said, staring at it. Of course it would just... be there. Why would the Gem bother with movement?

The information he was getting back let him know that his little bubble of air was bog-standard Earth atmospheric-at-sea-level—which meant there should be on order of ten-to-the-seventeenth helium atoms floating around in it. Sampling meant that he was picking up a much tinier fraction of those—in proportion with the tiny fractions that he was actually picking up of the other gasses that filled the space—but if he tried looking for that particular _signature_...

Data multiplied; the sampling fell apart and the Gem dumped all the raw information strait into his head—

_stop_

—but at least this time he didn’t fall over.

Right. Tony let out a breath. The Gem couldn’t sort, then. It didn’t have a mind of its own; searching was out. It needed to be actively directed. Maybe that was what the Window had done—or, again, maybe that was just a property of the Gap. It was easier to find a needle in a vacuum than in a haystack.

“You’re starting to creep me out here,” said Natasha, and Tony realized he’d been staring intently at the air for the past minute.

“Sorry. Trying to get a handle on it.”

“And?”

“It’s a no-go for finding Steve and Foster directly, but there might be one more thing...”

“What’s the catch?”

“I’d have to try it from the Ginnungagap.”

Natasha made a tiny ‘ah’ sound. “No backup.”

“If it went too wrong, you’d be stuck here.”

“Getting back to our Earth is not our biggest problem. Gaea will help, if it comes to that,” she said with confidence. “You should have a spotter here on this side if you can’t bring one along, though.”

A spotter? Been a long time since he’d had one of those—had he _ever_ had one of those? Did New York count? Probably. Before that... Rhodey, and before _that_ , Rhodey and Pepper still, but in entirely different ways. As far as a spotter for _science_ went...

If things had worked out differently, it might have been Bruce. Strange, that now it was Natasha.

“If you’re sure.” He pulled the armour from subspace, quieting it with the same trick Gaea had used yesterday. The Space Gem he slipped into a hollow sort of pocket at his hip, nanites secure all around it. _“If I don’t come back, don’t wait too long.”_

“Get on with it,” Natasha told him.

There was no need for the subspace bubble, not without a passenger along. He simply ripped open reality and fell unprotected into the Gap.

Without the distortion from the subspace bubble, and without Hel and panic to distract him, he could see the differences that viewing it through the Window had made. The false-stars shone brightly, as always, but now he could see that, really, they were just as near as they were distant. The Window, and the subspace bubble, made them look like stars in the void of space, but the Gap was the opposite of reality, not the mere absence of matter. Distance was defined only by the intrusion of what was real. Somewhere in here the Nidhogg lurked: an aspect of unreality that could not be intruded upon by anything real, and instead would destroy it instead, would devour him and everything else in the Cluster. Somewhere else...

He thought about the Gem, and thought about what else was in this place-outside-reality, beyond-reality, below-reality—structures and underpinnings made of barriers between nothingness and existence, but mostly it was just nothing. So what _was_ here, aside from him?

 _Power_.

Motes of power shaded in orange—familiar orange: he’d seen it flickering when he’d used the Window. The Window had shattered and the Time Gem had shattered... but it was here, in this place. It was nearly the only thing that really was. Tony let his awareness roll outward, across distance that should have been impossible, should have overloaded his memory the same way a mol of air had overwhelmed him in reality... except the Gap wasn’t organized along reality’s rules. There wasn’t matter here to get in his way, or the awareness of the vacuum between it—what he was looking for was far-flung across reality’s superstructures but right beside him here, and there was nothing else to distract him from it.

Orange light gathered before him as he reached out, calling it back. Bits of reality that had broken off of the superstructures intruded every so often—he pushed those away, excluding them before he could get lost in them. The Gem wouldn’t let him be unaware of it, but he moved past it. The light in front of him... wasn’t growing fast enough. It had gone asymptotic, now, and he was starting to strain the limits of his free memory.

_There has to be a better way than this. I have to be doing this wrong somehow._

Could he use an incomplete assembly of the Time Gem’s power to go... back in time? What, and retrieve the Time Gem from himself? He’d have dismissed that as a paradox, but the Space Gem was a paradox in itself, a tiny thing—a point, two points overlapping—that had dominion over every other point.

He had to try.

 _One second back,_ he thought, the visualization of a cesium atom ground state transitioning 9192631770 times. The light in his hand shone in his mind as well, and it must have been enough pieces of the Time Gem to matter, because he could feel time turn over, and the amount of pieces remaining in the Gap increased.

Further back. The light in the Gap became greater, and he gathered it up as he went. It would be darker in the future because he’d have taken it already—he hurtled further back, hours, days, and snatched the power of the Time Gem up, now forming nearly half of the whole. Further back and he had his half of the Gem, with more than half of the Gem remaining out in the Gap: he took all that he could reach and jumped further back. Its power was scattered back and forth along time-outside-reality, and somehow there was no paradox in him taking it from multiple points and smashing it all together. Was that because it was infinite?

Back at the point where the Gem’s power shone brightly, whole, and between the near-complete Time Gem in his right hand and the Space Gem at his hip, the whole of the Void was singing in his head—because there was nearly nothing in it, except the Time Gem. As he watched, it condensed, shattering-in-reverse: time seen backwards. Or maybe this was the forwards direction, and when it had shattered, that had been condensing-in-reverse, just seen from the wrong perspective...

Taking things from before he’d taken them: an acausal act, therefore an acausal system. But he _knew_ he could do it; the Gems assured him of it. He'd done it. Ergo, he was looking at all of this with the wrong rules. If it was truly an acausal system... signals travelling backwards and forwards at will... then he could look at time and space together, transformed, the same thing he’d been doing all month with Bruce’s impossible math—

The analysis ran in his head and through the twinned Gems, understanding like orange fire as everything shifted and suddenly the picture of Time shoved into his head. Backwards, forwards—in a different perspective, a different set of variables, and now it all crystallized. The Space Gem was a point and an infinity. The Time Gem was the same. All the points and places of the universe transformed, inverted, and his mind was scattered across the underpinnings of reality, stuck at the point where the Gem had been whole, watching himself try to enter the Window, crawl through it and change everything—

A loop, to the Time Gem, was many points existing all in the same place. Information dumped into his head, of all the times he’d tried to use the Window and flubbed the ending, all the times someone else had tried and—

—failed. The Window was broken bits of Time Gem, linked into a different form, a limited form. It couldn’t support the paradoxes forming now. If they collapsed, all that they encompassed would be annihilated, and altogether those layered points encompassed the entirety of the local cluster of multiverses.

He had to stop it. He was always going to stop it. He was always going to make himself fail, to fail himself. It all linked together, something less than inevitability and more than a plan, the power of the Time Gem to act in both directions.

If the idea of 'cutting things close' were applicable, that would be what he was doing, because everything was starting to break even as he thought about it. But he had all the time in the universe. The Font-Window-Tear was one over-stressed thread from total collapse in forward-time, but it wouldn’t collapse without him triggering it in reverse-time, without this one act. It was as impossible as the idea that he would not act.

He made the break deliberately, the iteration carefully chosen out of all those stacked-up points. A reflected wave was headed back at him from the other side of time, and the near-complete Time Gem showed him how to coordinate this new shockwave to have an extremely exact effect at two precise points in time—one of them now, for a given definition of ‘now’. One of them long ago. In between would merely change to match—but not too much. Civilizations could rise and fall along the crest of a wave in Time... or change just a little. He didn’t have to calculate exactly how little: he could see how it was all going to play out. The Lesser Evil became acceptable. A monk condoned torture of an unsouled being.

The light faded and was gone, taking with it another, more metaphorical kind of light. It left behind only a small, round gem, clenched tight in his fist: the Time Gem, stolen from before it had ever started breaking: even as, acausally, it broke, and all these events continued.

He was done here. The universe remained a little bit darker—and exactly as dark as it always had been. The change from that past point travelled forward, rippling off of the other changes that he had made, reflecting and refracting as he reverted to forward-time. A stupid mistake. He hit the loop again, and this time he saw everything in forwards-motion, saw all the failures, the deaths. Tripitaka spoke words of pain to smash him into the ground—words he couldn't feel from this lofty vantage; words that weren't directed now at _him—_ and he never learned. The toll rose, each iteration adding new failures—

_No._

This wasn't like before. He had the Time Gem now, and it was infinitely more stable than the Window that had been formed of its half-shattered state. Before he'd been running on desperation, and hadn't had access to the data he needed to figure out how to change things for the _better_ , or even if he could. But that didn't apply here. A thought was all it took to look backwards again. He began to look, methodical even in the face of so many of his own fuck-ups, and that was when his brain caught fire.

A familiar, white-burning haze. He'd heard Tripitaka's words across time and been unscathed, because they hadn't been meant for him, but somewhere out there somebody was now saying the mantra with _intent_.

Half his status signals flipped to fail-states. The headband was extremis, threaded through his entire being, and it suspended him on the brink of the abyss while the flesh was flayed from his skull and his skull was slowly ground to dust, leaving the fragments to grind into every ragged nerve. Thor had once spent an hour, an eternity, pulverizing every bone in his hands, one by one, and refused to let him fade out into the relief of unconsciousness; the Makluan headband did the same, but better, cleverer, because it was wired directly into his synapses. It could pour molten agony straight into his mind, and it did.

_nononononoSTOPAWAYAWAY_

All his muscles were seizing; the headband left him enough for full consciousness but not enough to move. He flailed, but every movement registered as damage that extremis translated as pain, and he tried to rip his scalp off and claw away the headband beneath, but he didn't know if he managed to move his arms. He screamed at the Gems, words failing and thought coming only as concepts, the need to flee, backed by inhuman agony and bitter betrayal.

The responses from the Gems he could feel—they were sharp and quick to respond, the knowledge dizzying as a kaleidoscope, an alternate way of looking at the universe while the headband kept him anchored to physical space and time. _Forward,_ he went, but the mantra didn't cease, and the marrow of his bones felt like it was igniting, consuming, and he couldn't think, and he begged _AWAY_ but he couldn't get away and it wouldn't stop. He fell through a sky of ash and then a sky of green and then a sky of coral, worlds in quick succession as he fled and it followed him, a merciless constant. He was screaming and he couldn't hear himself think and the sky went black and there were no stars, because he had failed in Maklu and Steve had failed him and Steve had _lied_ and everything was going to die, he had seen the end before and it would come again and he was losing his mind, extremis slipping out of control, the armour shredding off of him like razors clawing through his skin.

It stopped, then, and Tony drifted, stunned as much by the cessation as signal itself.

Time skipped. His awareness snapped back like a rubber band, no longer held to the headband's unforgiving rack, and he wasn't sure he hadn't passed out. He flailed, rebooting, seeing not-stars around him: the Gap. Extremis came back to him sluggishly. Nanites floated around him: the armour, half-decomposed. He became aware that he was trying to gasp for air and failing because there was no air. There was also no vacuum to pulverize the alveoli in his unprotected lungs, so his mouth was simply working open and shut like a fish's.

He wasn't looking at Time sideways any longer. The constellations of the Gap were no longer spread out for his mind to examine. With returning awareness came panic, not the irrational haze that had fogged him but the cold realization that he didn't have the Gems' perspective any longer.

 _shit_ Tony thought, still sluggish and floundering, flailing limbs as he tried to reconnect with disassociated nanites. A moment later he managed to grab some, and information flooded his brain. It was like getting a bucket of ice-water dumped over his head—uncomfortable, and it left him spluttering. The Space Gem was floating against some of the nanites that had comprised his left gauntlet, before the nanites had broken apart, and he managed to get a grip on it. But he'd lost hold of the Time Gem. Frantic again, he cast his mind into the Space Gem and spread it wide across the Gap.

Tony barely had time to realize he was too close to one of reality's substructures before data flooded his mind, overwhelming synapses not with pain but simply with a glut of information.

His perspective of the world flickered as his brain momentarily shorted out, and then there was light instead of the Gap and he was falling. There was matter and space and energy all around him, data slamming into his brain, and he barely managed to turn it off before he crashed a third time, systems overloaded.

He re-booted again just in time to crash literally, into cold and unforgiving rock. The Space Gem spun away from his open hand, a tiny point of colour immediately lost among the snow surrounding him. Extremis bleeped warnings at him even as it gave up and melted off his skin.

_Nnnoo, shhit_

He tried to get up. Pain and damage relays tripped, their data real this time, and Tony blacked out.

 

* * *

 

“Instead,” said Loki, “You’ll remember this—”

 

* * *

 

“The Temple of Uttermost Winds,” breathed Jane, staring with wide-eyed wonder at the aurora below. “Oh my god. It’s _solar_ wind.”

“Not quite,” said Loki. His whole posture radiated distaste, like a cat that had unexpectedly found itself surrounded by mud, with nowhere to step that wouldn’t make the muck on its paws worse. “ _Dr._ Foster. Those aren’t stars.”

She looked at him oddly. “What are they, then?”

“Thoughts. Observe.”

He gestured lazily, magic sparking about his fingertips, and the glass of the floor rose—and the water along with it, an inch that clung stubbornly even as the floor it was on turned sideways. Not water at all, maybe. Loki reached out and stuck his hands through it, flat against the glass he’d raised, and a green flash lit downward toward the blue aurora below.

Beneath Steve’s feet, the floor trembled, shifting like it had suddenly turned to taffy. He lurched, barely keeping his balance, and then fell again anyway as it vanished beneath him. His stomach lurched upward towards his ears and he tucked into a roll as gravity rebelled... and then he landed.

They were looking _up_ at the not-stars, now.

“They don’t look like stars,” said Jane, very quietly. “There’s something wrong about them.”

“Consider it a reflection on those who once lived here,” said Loki. “Now, where is it...” He was searching the aurora above, head thrown back. Steve eyed the sky, more warily, but the red glow of the Power Gem was nowhere to be seen. “Tell me!”

 _Gone,_ Steve heard.

_Stolen._

_Taken in the dark._

_It would have led them to us anyway..._

Loki’s face twisted with ugly rage; a moment later his expression was calm again, unperturbed. “Who stole it?”

_Tell you? Why should we?_

_A mystery..._

_An enigma._

“A lot of people are going to die if we don’t find that Gem,” said Steve. “Please, tell us. You’ll be helping yourselves as well.”

_We’re beyond..._

_...not quite beyond help._

_It doesn’t matter. It was Eaten. The unnamed... it will never be found again. It, alone, is safe... buried..._

Loki snarled, the rage bursting free of the mask he’d thrown over it. “Buried? You pathetic wretches! You blind cretins! I will find it, I will rip it from the bowls of whatever creature you let have it, and I will _bury_ you in the steaming entrails!”

The glass floor shook, the whole gigantic plain of it. Magic, power, hummed in the air, like the energy of an arc-reactor magnified a thousand-fold. Steve ducked beneath his shield, stumbling as he tried to shift back to cover Jane as well. Gravity went lopsided. On instinct, he raised his shield high instead, just in time for an enormous chunk of glass to smash against it, sending shards crashing down around him. The telescope above them was breaking.

“Loki!” cried Jane. “You’re going to kill us!”

Loki turned and his eyes were full of fire. “You are _useless_ to me,” he spat, and the portal spell he’d used before surrounded them—but different, this time. This time Loki wasn’t inside the spell with them, and it contracted unevenly, squeezing inward like giant fingers. Steve turned to shield Jane, with his shield and his whole body as well, and bones in his free arm snapped as the force came down on it first—his leg bruised, his shield shuddered—

 _Bury us..._ whispered the voices. _Yes._

_...they will never find us now._

Something slammed into the portal spell from above. Glass rained against the floor. And whatever imbalance there had been in the teleport was overcome, or overwhelmed, and the energy tore them away from the world.

Steve didn’t quite lose consciousness this time. Darkness pressed around him, and his head ached like he’d been repeatedly whacked over the head with a hammer, but he managed to keep hold of his senses. He felt like he’d been tossed in an automatic dryer—tossed around, dented, and wrung out. His right arm had gone numb starting from somewhere near his elbow. And the smell of garbage and exhaust fumes around them—

New York?

Jane, pressed up against him—or, well, he against her, since he’d been trying to shield her at the time—swayed, and made a noise like she was going to retch. Before she could, Steve tipped his shield forward so that it pressed against her forehead. It had worked last time.

“Oh, thank god,” Jane moaned, and pressed her whole face against it.

Steve rather wished he could do the same, but just then a car horn honked and made him aware of how awkward it would be. Squinting against the splitting pain in his head, he tried looking around instead. It was definitely New York, and thankfully they were in the mouth of an alley and not in the middle of the sidewalk or road. Ten feet away, businessmen and women passed in either direction, most of them talking on cell phones; further down the alley, a worker was loading bags of trash into a garbage truck.

“Oh my god,” said Jane, lifting her face away. “Uh, sorry. Wow. Did he actually—I thought we were dead. Did he actually send us _back?”_

“Looks like it,” said Steve, raising the shield to press against his face in turn. The ringing in his head faded immediately. _That’s my girl._

But Jane had turned white—whiter. She was already soaked through and stranded in New York in early spring; they needed pick-up before she went hypothermic. “No. I—I don’t think he did.”

Steve turned. Politeness dictated that he not block her view, but situational awareness made his nerves shriek about not adequately protecting the civilian, before he saw what she was looking at. It was a two-story high screen with ads, the current one for the new _Starkphone Nova 5: in stores May 4 th._ The oddly familiar female model holding the phone was staring down the camera, grinning with _I-know-something-you-don’t_ and just a _hint_ of being willing to share.

The Starkphone Nova _5_. Tony had been on version three... before he’d gone insane, been declared dead, and SI had gone bankrupt and had all its assets seized by the government.

“Holy shit,” said Jane, and that was when Steve realized exactly why the model was so familiar.


	12. Weapons of Words: 3.1

** PART 3: WEAPONS OF WORDS **

“Okay,” Jane said slowly. “We should call SHIELD. Or, um. Stark Industries, I guess, if we can’t get SHIELD. Maybe?”

Steve grimaced. He still had his comm—if it wasn’t fried after everything he’d put it through today—but even if somebody picked up on the other end, who would they be? “Not so fast. People here aren’t the people we know.” The billboard was definite proof of _that._ “The same protocols we set up for identification in SWORD apply.”

“That’s a lot easier to say when we’ve got a transdimensional window to look through,” Jane muttered. She glanced down at herself, hugging her arms to her chest, and then looked over at Steve. Her shivering shifted to shock again. “Oh, god! Shit, your arm!”

Steve had been trying not to think about his arm, and as soon as he did, a wave of pain rolled up from it. Definitely a compound fracture. Damn Loki. “It’s not too bad, I heal fast. Information needs to be our first priority.” He was pretty sure there was a triangle bandage in the tiny, ultra-compressed first-aid kid he had loaded in his belt-pockets. Unfortunately, that was on his bad side, and he had to fumble for it. To keep his mind off of how this was jostling his arm, he continued, “Public library’s probably our best bet, but we won’t be inconspicuous while we’re getting there.”

His current suit wasn’t quite as bright as the one he’d been given when he’d first woken up in this century, but it wasn’t civilian wear, either. And it was sort of hard to hide his shield without a proper cover. He could take off his outer jacket and hang it over-top, maybe, except that would involve taking off his jacket over his broken arm, and even if he could have managed that Jane was in greater need of his jacket than his shield was.

“Oh, jeez, let me help you with that,” said Jane, watching him fumble for the tiny shrink-wrapped package. He gave it over to her gratefully, and between the pair of them they managed to rig up a sling. He wished he had a proper brace, too, but a sling was a start, even if putting his arm into it made his head swim. His uniform sleeve would just have to provide enough bracing for now.

A strange _thwipp_ ing noise above them made him look up just in time to see an extremely oddly-dressed person drop head-first out of the sky, trailing a grey rope that really didn’t look up to bungee-jumping. Steve shoved Jane back and was half-positioning himself to try to catch the idiot—which probably made him more of an idiot—when the rope proved stronger than it looked and slowed the person until they were hanging upside down, legs tucked into a weird cross-legged position, swaying gently back and forth on their line like a bob at the end of a pendulum. Like this, Steve could see that the stranger had a black, stylized spider their on his chest, and a definite web-theme going on throughout the rest of the red-and-blue costume. _Hang on... that ‘rope’..._

“Cap!” the newcomer—male, young, New York native but not from Brooklyn—exclaimed. “What the heck happened—you’re hurt—is there a bad guy I need to go after, uh, somebody getting away, because I don’t see who hurt you and you’re totally not Captain America,” he finished, somehow making squinty suspicious eyes at him despite wearing a mask.

“Uh,” Steve said, because his brain was stuck on, _What?_ Was this actually a person with... spider-powers? Or merely some type of elite agent, like Clint or Natasha, who had gone and lost his mind? “Not in the way you mean, no.”

“Okay... imitator? Because I have to say, breaking your arm first day out, not a good start, also this is kinda illegal nowadays unless you’re properly trained for _exactly this reason_ , and—”

“Is there a nuclear war on?” Jane demanded. She was looking a bit wild-eyed.

The spider-person swung back a bit on his web. “Uh. _No?_ Although, since the Republicans swept Congress in the last election—”

“But America’s still democratic?” asked Steve, because they’d run across more worlds than he wanted to think about where America was a fascist dictatorship.

“If you’re ignoring the repeal of the Voting Rights Act, sure,” and he sounded so indignant about it that Steve found himself relaxing, even if he couldn’t help but think, _What?_ How the Hell had anyone in the government gotten it into their heads that repealing the Voting Rights Act was a good thing?

Was he on that side? “Would Captain America approve of the government oppressing minorities?”

“Okay, I’m not really certain where you’re going with this, but if you’re trying to argue your way out of registering, I have bad news for you, dude,” the spider-person informed him.

“I’m not,” said Steve, although maybe he should be. ‘Registering’? “Please, just answer the question.”

“That wasn’t a—” The mask’s white eyes managed to widen dramatically. Was it glued to his face? “Okay, clone or alternate reality? Clone—no, don’t worry!” he added quickly, and Steve lowered the shield—he’d raised it on reflex. “So I’m guessing clone by the way you’re so jumpy, but if you got cloned by bad guys we can help, clones totally have the same rights as people these days. Uh, that is, the same as non-cloned people, clones are people too—it’ll be fine, trust me! I mean, nobody’s going to be happy with the people who cloned you, but that’s not _your_ fault and can I call the Avengers or is that going to freak you out? Other Avengers. I mean. Because I am one. Uh, so, you can trust me, you know.”

Steve shared a look with Jane. She looked cold, wet, and miserable. He couldn’t say he felt too great himself. The idea of being able to place his trust in these people was tempting, but even if the spider-person _sounded_ sincere...

_Oh, Hell. They’re not all Loki._

“Yeah,” said Steve, sighing. “You’d better call them.”

“Okay, great,” said the spider-person, flipping right-side up and dropping away from his... web-rope. It fluttered back to lie along one wall. Now that he was no longer being a contortionist, it was easy to see that the guy was actually a pretty small fellow, maybe Natasha’s height. Steve made a mental note not to underestimate his strength, though: anyone who could do those acrobatics had to be strong. From a pocket somewhere on his person—Steve wasn’t sure he wanted to think about _where_ —the spider-person took out a small, compact smartphone. “It’ll be just a sec. Sooo... do you have an actual name? And, sorry, are you a clone too, or are you a bystander?” This last question was directed at Jane, in a friendly manner.

“ _Spider-Man? What’s up?”_ said a very familiar voice over the phone, before either Steve or Jane could answer. Spider-Man’s mask’s eyes widened again comically.

“Uh, Cap. Well, you see, I seem to have stumbled across your, um—”

“Alternate reality,” said Steve, before Spider-Man could mis-identify them.

“—counterpart from an alternate reality.” He looked to Jane again, and she nodded, still shivering. “Two of them. Two people, I mean, only one is you—there aren’t any more people with you, right?” he asked them.

“Just us,” said Steve, perhaps more grimly than it was worth.

“Right, two, he’s got a broken arm and they’ve both taken a dip in the Hudson, they’re frozen,” Spider-Man finished, in a surprisingly professional manner.

“ _Right,”_ said the other Steve. _“I’m on my way. Confirmed non-hostile?”_

“Maybe a bit paranoid,” said Spider-Man. His eyes were narrowed again. “Is there someone after you?”

Steve shook his head. “No, we got, uh, kicked here,” he said, not sure how to explain it, or explaining it was even a good idea. “Hopefully our friends will be looking for us.”

“Okay, then I gotta ask—is _your_ US government no longer a democracy? Technically a republic? Because usually when we get alternate reality people in here, they’re pretty confused, yes, but that’s not really their first question. I mean, sometimes they think we’re evil, which is annoying because then we inevitably wind up fighting and somebody always yells at me after for getting webbing on them, and sometimes _we_ think _they’re_ evil, but—”

“The US is doing fine,” Steve cut in, when it seemed like he wouldn’t be able to get a word in edgewise unless he just talked over-top of him. Was this how the guy normally was? If he was an Avenger, it would be a good thing to find out. “We’ve just had some bad experiences with other realities, before.” Jane made a face and nodded.

“Right, gotcha—”

The whine of repulsors cut through the air, and this time it was a more familiar figure who dropped out of the air, landing in one of Iron Man’s trade-mark three-point landings. And... it did _look_ like Iron Man—there was no hint of femininity in the suit. Steve glanced over at the billboard again. Maybe he’d been mistaken? Maybe it was a relative?

The faceplate flipped up, and they were face-to-face with an undeniably female version of Tony Stark. The lines of Tony's face, handsome on a man, translated to be just as striking and just as recognizable on a woman—but it was her _expression_ , the bright, only slightly mocking curiosity in her regard, which made it plain as day. There was no way that this was a relative, or anyone except Tony him—herself.

Steve took a moment to blink and let his worldview resettle.

“Hey,” said not-Tony. Curiosity shifted to startled wonder and more than a little bit of... covetousness? What? But then she looked past Steve, to Jane. “Shit. Jane? Are you okay?”

Jane was staring back with a completely weirded out expression on her face.

“Okay, I feel like I should say that we know that Iron Man’s occasionally crazy or a villain, uh, but here she’s on the good side, hand-on-heart,” said Spider-Man, suiting action to words.

“Yeah,” said Jane faintly, “It’s just—that’s... weird, that’s—” She clapped a hand over her mouth, wide-eyed and blushing.

“O-kay,” said not-Tony slowly, and she opened a small container cell in the underside of one of her forearms, pulling out and shaking out a silvery thermal blanket. “Maybe you should take this, you look drenched.”

“Sorry,” said Steve, aware that he was staring, although not as badly as Jane still was. Jane did take the blanket with her free hand, but she was still blushing. “Uh, you’re, um, a guy, in our universe.”

Not-Tony blinked. “I am? Huh. First time for everything.” Her gaze slid sideways, her head tilting—she was hearing something that he couldn’t. “Yeah, there’s an opening at the end of the alley—see it? Good, we’ll go over there. Come on, kids.” Her focus snapped back to them all, and, _kids?_ “Steve’s gonna park the jet in the clear spot over there, and then we can vamoose.” She nodded at where the garbage truck had been.

 

* * *

 

The Tower in this world didn’t look much like the one in their own: it was a more rectangular design, tiered instead of thinning, and nearly a third as tall again, looming over the surrounding skyscrapers in a truly ridiculous fashion. It was different enough that it shouldn’t have been painful to look at, but something about seeing the name STARK emblazoned across the top, albeit in a more decorous font, made a lump form in Steve’s throat. After they’d risen into the air, he was glad to just sit and listen to Spider-Man rambling on about minority voting rights while Natasha-call-me-Tony Stark—but Steve couldn’t; he felt a bit bad about it but he _had_ to think of her as Toni-with-an-i, slightly brighter, a bit less pinched around the eyes—pulled out some fancy medical equipment and set Steve’s broken arm.

“Huh,” she said, staring at his arm. Her eyes were unfocused. Was it possible that she had something like extremis? “Do you have a healing factor?”

He nodded. “Broken arm’s about a day.”

She whistled between her teeth, but didn’t say anything more before clamping a cast around it and helping him put on a proper sling, then handing him some painkillers. It wasn’t anywhere near a large enough dose to actually take a bite out of the pain, but he took them without comment. Now that the arm had been set, it wasn’t so bad, and Steve preferred to be clear-headed.

They landed about a minute later on the highest helicopter pad—because this Tower had three—and Toni led them down the ramp and into a wide, open area elevator, while Other-Steve—Other-Other-Steve?—ran through the post-flight check-off. Spider-Man, meanwhile, jumped off the edge of the Tower, caught himself on a web-rope, and swung away with a whoop. Judging from the way neither Toni nor Other-Steve paid him any attention, this was nothing to worry about, so after a second Steve made himself stop staring and follow Toni.

“Okay,” Toni said briskly. “First, lab. Not to make experiments of you, but we really do need to check that you’re not clones, Skrulls, or mental projections. If you were _actually_ swimming in the Hudson, we also need to get you on a course of antibiotics. Plus, of course, scans to figure out if we can get you back to where you came from—Spidey made it sound like an accident?”

“An accident on our part, anyway,” said Steve. He looked over to Jane, who was still wrapped in her foil blanket. “AED still working?”

“Oh!” Jane pulled it out and pushed a button. A LED haphazardly glued to the side of it turned on.

The reaction from Toni made Steve realize that this was the first time that they’d had her full attention. She straightened up, her gaze intense with interest, and some sort of light beam shot out from her suit and scanned over the AED and Jane’s hands. “What the heck is that?”

“It’s a—” Jane fumbled for a moment, looking helplessly at Steve. “Oh, god, I can’t even remember what the acronym stands for.”

“Anti-Eavesdropping Device.”

“Not a defibrillator, gotcha,” said Toni. “From what I can see, that goes way beyond the types of signal jamming that I’m familiar with. May I?” She held out her hand.

Jane grimaced, but handed it over. Toni took it to examine curiously, turning it over and about.

“Who built this?” she murmured. “Or is this Asgardian?”

“I built it.” Jane bristled.

“I take it you’re not a nurse on your world.”

“A nurse?” There was something about the way she said it that made _Steve_ want to bristle; nursing was a damned difficult job. “No, I’m an astrophysicist. _Dr._ Jane Foster.”

“Well, that’s different,” said Toni cheerfully. “Beautiful work, Dr. Foster—I’m seriously impressed, I have no idea what half of this thing does.” Her eyes, overtop of her smile, were serious. “You can understand why I’m a bit concerned about unknown tech.”

The elevator reached its destination and the doors opened with a ping, revealing a sight that made Steve need to swallow, hard, several times. Toni’s workshop. It looked so damnably similar to Tony's, back before everything had fallen apart.

“It prevents people from eavesdropping,” said Jane, shuffling out of the elevator ahead of Steve, and eyeing her device in Toni’s hands. “I—okay, are we doing this?” She turned back to Steve. “Telling them?”

Steve couldn’t quite tear his eyes away from the holographic displays hanging idly near one wall. The layout wasn’t exactly the same—of course not—but there was an old couch in one corner, indented because Steve had only ever sat in it facing the one direction, and... he shook his head, trying to clear his thoughts, and realized what that looked like and held up a hand. “Sorry. Seeing this—”

He faltered, and Toni raised an eyebrow. Jane just looked confused. Steve shook his head and brought his thoughts to order.

The WSC had been dragging their feet for weeks about approving the next step toward contact with another Earth, and here was a golden opportunity. There were better candidates out there for a first alliance—worlds that they knew so much more about—but, Hell, Steve was here and this world... no, he didn’t know too much about it. But that was half the point of contact. Their New York was bright and beautiful and they had good people not too afraid to help lost strangers. In the battle against Thanos, they’d be useful allies. That was good enough for him.

“Telling us what?” prompted Toni.

Steve squared his shoulders and focused on her, rather than the workshop. “I don’t know how much you may be aware of it, but there are problems in the multiverse cluster right now—problems that affect all realities. The gods of Earth have cut off their realms.” Funny, how he didn’t even stumble over that phrase now. “AIs are going insane. There’s been dimensional problems—Jane, you’d better be the one to explain that.”

“Uh, right,” said Jane. “We’re seeing frequent collapse of—” Steve wasn’t quite sure what she said after that, but it took a solid minute, and Toni nodded along, so presumably she understood. “Most of it,” Jane concluded, “we think can be pinpointed to the Euclid Paradox.”

“Euclid’s Paradox?”

Jane made a motion of denial. “Not, um, the traditional one. A few weeks ago, the Tony Stark and Bruce Banner of our world”—Toni didn’t blink at the name; maybe there was a Bruce here, then, or maybe not—“They, uh, it’ll take me a while to write down the full proof, but they have two different proofs that wind up like...” She looked around; Toni flicked her fingers and a holographic screen popped up. “Thanks,” said Jane, and wrote out a dozen lines of Greek symbols.

When they were done, Toni wandered over and stared at it. “Until I actually see the math, my gut instinct is that obviously there’s something wrong in the proof...” she murmured.

“It’s gone global on our world, and nobody’s managed to pick out a problem yet,” said Jane grimly.

“Hm. So, you wound up here by accident, but you were trying to go _somewhere,_ ” said Toni, waving the screen over to a wall so that they weren’t all staring through it at each other.

“No, this really wasn’t intended,” Steve assured her. “But since we’re here anyway—on our world, we’re putting together an outreach program. We want to get the best and brightest minds of humanity together... to stop Thanos from destroying the multiverse.”

“Stop Thanos,” Toni murmured. “Thanos. Where have I heard that name before?” Her eyes went distant, but she kept talking. “I’m not saying it’s a bad idea...”

“—but there’s usually things in the way that keep realities from properly working together?” Steve guessed.

“Yeah. Look, you’re—younger, no offence. I don’t know how much experience with alternate realities you’ve had before now—”

“A bit,” said Steve dryly.

“I can tell. It’s hard enough for two realities to work together. Bringing a whole _bunch_ of them in? Things break down, communication problems crop up where they ordinarily wouldn’t—”

“I know. It’s enforced by the Living Tribunal, to help keep realities separate from each other. But the Living Tribunal is dead.”

“It’s _what_.”

“Thanos destroyed it last month, in Maklu.”

“Shit, you’re not kidding.” Toni stared at him for a moment longer, and then raised her voice; Steve heard a speaker engage. “Honey? We need you down here. Our new friends have word of an omega-class threat. We’re going to need worldwide Assembly on this one _._ ”

 

* * *

 

A crackling pain shot through Tony’s limbs, and he came to with a choked-off cry.

Static haze was blanking out... things. His eyes fluttered open, but there was just a blur in front of him—darker on his left, lighter on his right—until something impacted his shoulder and sent him flipping around to stare... upward, bright light beating down. A smaller dark blur moved into his vision and he squinted, but to no avail.

It was... cold. He didn’t know how cold.

“Well, well, well,” said a voice—maybe the blur. It was... there was something...

He needed extremis. Extremis. What had happened to it? He reached out—

The world blinked out again.

 

* * *

 

The device that Toni was currently pointing at Steve beeped and lit up green. “Okay, not a shapeshifting alien.”

That was a possibility? Steve almost wanted to ask, but... on second thought, as she pointed the device now at Jane, he decided that if there was a scan to test for it, it was probably a stupid question.

Other-Steve, halfway across the room, caught Steve’s eye and gave him a wry smile, apparently reading the thought on his face. Steve shrugged.

“Yes, it has been a problem,” said Toni absently, reading him just as well—without even looking at him. “Jane, do you mind if I configure—”

“No, go ahead,” said Jane, shoving back the chair from the desk she was at. “I’m really not used to this set-up—”

“It’s pretty customized, sorry—”

“Reed,” said Other-Steve, speaking now to a holographic screen, where a familiar face had appeared—Dr. Reed Richards. So, there was a version of him here... Steve mulled over the implications of that. He’d checked, after returning from ULTRON’s world, but as far as the SHIELD information retrieval team had been able to tell, Reed Richards had never existed. But here he was again.

In that first world, Reed had been one of a team of superheroes who had saved Steve's life, and been pretty damn knowledgeable about the multi-verse. Steve hoped it was a good sign.

“ _Steve,”_ said Reed, sounding mildly surprised. _“And Steve. One of those days?”_

“ _I’m already running a search for where they come from. Fortunately, Dr. Foster also came along, and she has a good idea of what their local group looks like, so it should go pretty quick,”_ said a highly mechanized voice, originating from... apparently, a holographic avatar of the Iron Man suit’s helmet, now floating alongside Reed’s head on the screen.

Steve looked between the screen, Other-Steve, and where Toni and Jane had their heads bent together over the other computer bank. _She_ does _have extremis._

But how? Extremis had been Hansen’s invention originally, but it had had alien input, which they now knew was Makluan. Tony’s most recent iteration had had even more of that. And Maklu was at the centre of the multiverses—how could Toni have a working version of extremis without knowing about everything else?

Other-Steve was explained the situation to Reed, and shortly they were joined by more holographic floating heads. Toni kept working with Jane, until they finished doing whatever-it-was that they needed to do to start the search for how to get back home, and then Jane stepped forward, speaking to the faces crowded around her—nervously, but then with increasing confidence as the conversation devolved into something that sounded like a lot of bizarre mathematics. A holographic whiteboard winked into existence, and swiftly became covered in holographic ink. The Iron Man avatar continued to participate, but Toni, her physical self, seemed to be barely paying attention, except occasionally to point another device at Steve or Jane, with muttered explanations of what they did—“Not susceptible to Kree quelesh flu, good, we won’t have to worry about you meeting Carol—”

Steve’s counterpart had also stepped back from the conversation, but only to start calling up other costumed superheroes, one at a time. Or at least Steve assumed they were superheroes—they were definitely costumed. People on this world seemed to like spandex an awful lot. Steve did a mental double-take as he recognized Clint, wearing a hell of a lot more purple than Clint had ever worn in his world, and with a pointy-eared mask that didn’t really disguise his features.

“Three P.M. You’ll be there?” Other-Steve was asking.

“ _That’s lunch time over here. Are you really asking us to skip a team lunch? It’s important bonding time, dontcha know.”_

“Eat early.”

Clint’s expression was surprised. _“What’s going on, Cap?”_

Other-Steve glanced over. Steve had carefully placed himself outside the blue light that—he was pretty sure—indicated the viewing angle for the person on the holographic screen; he shrugged, not sure what his other self was asking.

“ _Yeah, yeah, wait for the meeting,”_ sighed Clint. _“We’ll be there.”_ His image winked out.

At three o’clock, after having been thoroughly grilled by the science crowd, Steve realized that he’d been mistaken about how many superheroes lived on this world: the ones that Other-Steve had been talking to were just the _team leaders_. The already-massive conference room they’d moved to was packed full of holographic avatars—hundreds of them, and half the costumes were eye-wateringly _ridiculous_. Helpfully, floating nametags with affiliations appeared by each person’s avatar, and the teams were generally clustered together, but even so there were more than Steve could track. There were the Avengers, led by Rhodey—a fine choice, although Steve wondered that neither Toni nor Other-Steve was part of the team; the New Avengers, led by an—at last—sensibly dressed man named Luke Cage (unless that was his alias?); the Mighty Avengers, led by the slightly less sensibly dressed Carol Danvers; the West Coast Avengers, led by Clint (whose full costume apparently included a leather _kilt_ )—“How many Avengers teams do you have?” Steve asked his counterpart.

“Six,” said Other-Steve. “And we draw on the Fifty State Initiative as we need. After Registration passed—”

“Registration?”

“Of superheroic identities. They wanted to make it _abilities_ , but we were never going to allow that. There was a lot in the original proposal that was shady, but we took it apart and put it back together right in the end.” He smiled over at Toni—who, with Jane, was surrounded by a crowd of blue holographic scientists—with a look of such adoring fondness that Steve found himself doing yet another mental double-take. Were they...? “It’s paid off. We don’t have show-boaters or untrained kids running into the line of fire anymore. The last time Earth was invaded, we kicked ‘em out inside an afternoon with no fatalities.”

No fatalities... New York was _still_ reeling from the Chitauri invasion. The death toll had been in the thousands. Steve felt a stab of irrational resentment, and then one of deep envy.

“But neither you nor Toni...?”

“No,” said Other-Steve, with another of those adoring smiles directed at Toni. “We decided to take a year off after the wedding—and then between sorting out Registration, and coordinating with everyone, there just isn't time. Both of us are on reserves pretty much everywhere. We go all over.”

_Wedding._

That answered that question.

With some effort, Steve made himself look away. He was just going to have to think about that... later. Right now, there was plenty stranger all around him, and he needed his head in the game. Fortunately, if there was one thing to be said for the local weirdness, it was that it certainly provided a distraction. 

There were at least three kings in attendance, two of whom were included in the science crowd and one of which lived on the moon. The third king was from Atlantis, the actual underwater city of legend, which was emphasized by the speedo he wore (?!). There were three (or was it four?) teams of various ‘X-Men’, who all stood rather apart from the rest of the heroes except for the scientists—all clustered together in the middle—which led Other-Steve to explain that this world had existing prejudices against some superhumans based on how they got their powers—just in case Steve had thought this world was all roses.

There were teams from other countries: _‘Alpha Flight—Canada’_ and _‘Knights of Pendragon—Britain’_ , and then teams with English subtitles beneath their names: _‘Big Hero 6—Japan’, ‘Winter Guard—Russia’,_ and on and on, all the way down to, _‘Task Force—European Union’,_ which had a whole paragraph of different translations of the name _._ There was even a _‘Guardians of the Galaxy—Milky Way’_ , whose members included a giant tree and a sentient raccoon, putting most of the rest of the weirdness to shame.

A truly international—interstellar?—assembly. And most of them seemed to get along, holograms chatting casually to each other, although there were clear divides throughout the room. But altogether...

“Wow,” said Steve quietly.

Other-Steve smiled. “It is something, isn’t it?”

By the time new holograms stopped winking in, the room was full to the brim, with holograms occasionally doubling over each other as they crowded together. Toni, in full Iron Man armour with the faceplate down, stepped onto a raised podium at the front.

“ _Okay, Avengers—and honoraries and liaisons—listen up. We’ve got a pan-reality omega level threat here. A couple hours ago, we received unexpected visitors from another reality”_ — Toni nodded to Jane and Steve, immediately garnering them curious looks _—“warning us of a threat known as Thanos, aka the Mad Titan, bent on multiuniversal conquest or annihilation. Since then Reed and I have checked the data Dr. Foster brought with her, and we agree with her conclusions. This entity is a real and present threat.”_

“ _Very present,”_ said the foremost man from the Guardians of the Galaxy. He looked exhausted. _“This is seriously the first you’re hearing of this guy? We’ve had fifty-six planets activate Galactus evacuation protocols fleeing this guy in the last month, and none of them made it. We picked up a few survivors from one, but...”_

“What are the interstellar empires doing about it?” asked Other-Steve.

“ _At this point? Panicking.”_

“ _He has forces spread across countless other universes,”_ said Toni. _“This is a power beyond any we’ve seen before. So we’re going to need something new to fight it, or something very, very old. The scientists among us will be pooling ideas, but everyone here has seen some pretty weird shit—and so have your teams. Artifacts from the dawn of time, Galaxy-crackers, atom-smashers—any type of secret powerful whatever, now’s the time to collect ‘em. Even if they shouldn’t be used, if we can reverse engineer something from the principles of it...”_

“We’re that far up shit creek?” Clint called.

“ _The bastard’s destroyed fleets from half the empires in the Intergalactic Council,”_ said the Guardian. _“They’ll be_ thrilled _to know that when he pulls a spare battle group from nowhere mid-battle, it’s from an_ alternate reality _.”_

“Earth has never had a standing space force,” said Other-Steve, drawing all eyes back to the front of the room. Steve felt almost removed from him, watching—he could see the confidence fuelling his counterpart, the belief... “We’ve faced down Galactus without flinching and without abandoning Earth. If this Titan’s fleet comes here, then we’ll meet it and take it down. We need all teams ready for that possibility. His ships _can_ be destroyed.”

“ _As for ganking the guy himself,_ ” said Toni, _“we’re open to ideas.”_

 

* * *

 

When Tony tried to open his eyes, they resisted like his eyelids had been glued to his eyeballs.

He squeezed them shut, then tried a second time. _Where the hell...?_

Extremis. Extremis had to be—he reached out and hit a choking wall of static. There was nothing. The inside of his own head was... fuzzy. The ceiling above him, too—no, wait, that was just regular human eyesight. _Shit_.

With some deep instinct that he hadn’t known he’d developed, he realized he was in a cave—or, somewhere underground with too much damn stone, anyway. The air was cool, damp, and he couldn’t hear anyone else around. He was lying on a cot, on his back, and for a moment he had to paw at his chest—

“Relax,” said a voice, and he nearly choked. “I managed to convince Tem to leave it alone.”

Tony sat up, slowly enough to avoid making his head spin. The blanket falling away from his chest notified him of the fact that he was completely naked beneath it. _That’s what I get for using extremis for clothes. Shit._

“Maya,” he said, and then had to cough. His throat was really dry. How had he not noticed that first?

He couldn’t quite pick her out, until she spoke again. “There’s clothes at the foot of the bed.” She was in the much-better-illuminated part of the... workshop, behind a desk, peering at the laptop she had open next to some machine—he couldn’t see from this angle what it was. Extremis—

Same wall of static, and this time a burst of pain, starting from his neck and radiating down toward the arc reactor. He doubled over with a grunt.

Maya didn’t say anything. Maybe she hadn’t heard. Human hearing was—fuck, he couldn’t remember.

His hands were shaking as he raised them to his neck, feeling the cold metal collar that he hadn’t noticed before. Somehow. This strange disconnection from his own skin was a problem, then. The collar was solid, lightweight, and smooth around the entire construction; there was no seam... as far as he could tell. That didn’t mean much. He swung his feet over the edge of the bed, carefully, trying to feel it as they hit the floor. Everything was so _distant_. Missing extremis felt like gaining a second hole in his chest.

He almost, _almost_ allowed himself to wonder if this second collar could block the effects of the first, but months of careful habit stopped him, saving him from the migraine before it could begin. There was no such saving grace when it came to remembering what had happened just before he'd passed out.

Someone had used the mantra, and even the Time and Space Gems hadn't saved him.

The knowledge was a noose tightening around his throat, the death of a hope he hadn't dared let himself think. A sense of betrayal flared in his gut and then died. The only person left who knew the mantra was... but Loki might have read it in his own thoughts. Must have.

Tony sat on the edge of the cot and stared numbly at his fingers. He was naked. Was he cold? Yes. He stumbled on the first step, but made it to the foot of the bed, where a pile of clothes had been tossed haphazardly on top of a crate. They were obviously second-hand; his skin crawled at the thought of putting them on.

_You’re in a fucking cave._

Methodically, he dressed. There weren’t any shoes—shitty workshop safety, there. Three shirts—the first was too small, but he pulled it on and then the other two overtop. As he was fiddling with the buttons on the last, he asked, “Why the fuck in a cave, Maya?”

“They make good hiding spots.” She didn’t lift her head.

“Right.” The clothes had been cold. It would take time for him to warm up. He rubbed his hands along his arms—this was a step downward, even; the last time he’d done this he’d at least been given a hat, but this time they'd given him a collar instead. _Shit_. Giggles rose in his throat, and he had to clamp his teeth together to prevent them from getting out. No grown adult should be fucking _giggling_ , _get a hold of yourself_ , _Jesus fucking Christ._

“This your work, or Tem’s?” he asked, when he was reasonably sure he wasn’t going to open his mouth and start shrieking like a toddler.

Gaea had said that Loki couldn’t corrupt extremis, that even he couldn’t really _break_ it, for all that his emotional compromises were fucking up the data left-right-and-centre. But she hadn’t said it couldn’t be suppressed—just like it had been by that Thanatosian weapon back in Maklu.

“A bit of both,” said Maya. She sounded distracted. “A bit... gimme a second.”

Scientist at work. He took a better look at his surroundings in the meantime. The cot had a metal mesh base, and since Maya was busy, he liberated a few wires; in a pinch they might work as lock-picks. The crate turned out to be empty. There were no tools over on ‘his’ side of the workshop, the dimly lit side—they were all past where the neon lights began. Maya’s laptop was the only thing with a monitor, and she looked to be taking notes on _paper_ , although some of the other devices in the room _had_ to be more high-tech: low-tech was useless when it came to extremis.

He went over to examine the door, which incidentally took him over onto Maya’s side of the room. She didn’t twitch. The door was barred from the outside, which maybe explained why. But they couldn’t possibly be setting up a situation like that... not with her.

The angle from the door let him identify the equipment. Maya was working at a tabletop SEM with the COMEX label branded on the side. Had to be a recent model, from the dimensions. There were other imaging devices on the other desks around, profilometers and spectrometers and ordinary optical microscopes. Lists started compiling in his mind, independent of any real conscious thought, of all the things he could build if he took apart each one. On the other hand, there was no soldering station—unless there was a spare iron tossed in a drawer—and no way to do welding.

_And no point._

No. He couldn't think like that. He'd promised Steve—

He was going to go down fighting, damn it.

What he really needed was a way to get the damn collar off, or at least figure out how it worked. Sadly, his neck was a bit too large to shove into any of the machines here.

Tony went back over to the cot and sat down, pulling the blanket around his shoulders and across his chest, hunching over. It wasn’t quite the comfort that curling up into a tiny ball would have been, but that was a ridiculous impulse. And curling up like that wouldn’t have left him any room to unscrew the reactor beneath the blanket, and then fiddle with the ICG attached to its base.

He was done by the time Maya pushed her chair back and finally looked up. He studied her face. She’d gotten her first few grey hairs in prison, but they’d multiplied now, and she looked pale—washed-out, sun-deprived, hollow. Anemic. The bags beneath her eyes and the lines on her face spoke to exactly how much sleep she was getting.

“You look good,” she said.

It was such a useless question, but he had to ask it anyway. “Why, Maya?”

“Hey, you came after us, here,” she said, crossing her arms. “Apparently in shit condition, from the way you fell out of the sky. If we hadn’t picked you up out of the middle of nowhere, you’d probably have frozen to death. Or not. _Your_ extremis works, after all.”

That hadn’t been what he was asking.

“ _Worked_ ,” he corrected her. “You seem to have had a trick up your sleeve I didn’t know about.”

“Hey, it's just like you told me.” She smiled, bitterly. “Always easier to break than to build.”

“ _Why_ , Maya?” he asked, softly, and he knew by the pain in her eyes that she realized what he was really asking.

She looked away. Her tone was brisk, but she couldn’t seem to make herself meet his eyes. “It doesn’t really matter now, does it? We’re here, you’re here—”

“Twenty million people are dead.” _Does it matter when they're all going to die?_

It had to.

“It wasn’t _supposed_ to—it hadn’t exhibited that behaviour before, spreading like that. It was _supposed_ to just cover our escape.” She shook her head. “We learned from that. The ones who adapted better than the others—I am _this close_ to unlocking it. But here you are. And you’ve already got the perfected version.”

There was no jealousy in her fevered gaze, only the focus of a fanatic. A stressed, tired, over-worked fanatic, who apparently had been stuck in a cave for at least three months. Hmm.

“Demonstrated previously unseen behaviour—you haven’t questioned why, yet?” Tony paused. “Tem told you about the _dragon_ , right?”

“Of course he told me. If you hadn’t been acting so erratic he’d have told you, too. Not that you needed Fin’s help.”

“His name is actually Fin Fang Foom?” Tony asked, incredulous.

“His real name is unpronounceable. We call him Fin.” She studied him. “Are you going to help us?”

“Maya, this killed twenty million people.”

“ _Fifty_ million die every year. Extremis can put an end to that.”

Was there any remorse in her expression? The slightest amount of regret? He couldn’t tell. He didn’t know what her body temperature was, or her heartbeat, or what her brainwaves were doing. He was blind.

A long time ago, he’d made judgments of character on his human senses alone. Usually it had turned out terribly. But he’d also managed to work up an escape plan that had... almost worked. This time, he had no sure ally. If he could just get her to _see,_ then maybe, but he’d be unable to trust her _._ And if he couldn’t even do that much... Tony studied her back, and tried to ignore the sick feeling in his gut. If he had to go through her to get out of here—could he?

He didn’t have to think too long to know what the answer to that was.

_Second verse, same as the first._

“No.”

“We already have all the nanites you were wearing, and samples of the ones in your body,” said Maya. “We’ll crack it eventually with you or without.”

“Then it doesn’t really matter that I refuse.” It really didn’t. They could have extremis, in the end—Maklu-based extremis was a hell of a lot less corruptible than anything that had started from human tech, and it didn’t make zombies. Or superzombies. It wasn't a public health menace. But the _extra_ things he had... the Makluan reactor, the ICG, and the subspace inducers: those were the three things he couldn’t dissolve into extremis nanites. Two of those he still had. The third, if he was lucky, had broken when he'd crashed. That probably meant it hadn't.

“Tony, if you aren’t useful, then you aren’t _useful_. And we’re not stupid enough to think you’re not a threat. If _I_ can’t convince you... Tony, please.”

“I refuse.”

She was staring at him. “Come on! I can see you want to say yes—you know what he’ll do if you don’t.”

He _did_ want to say yes. He wanted to say yes so badly that he was shaking, micro-tremors running through his entire body and making the edges of the arc reactor dig into the pads of his fingers. It didn't matter that nothing they could do to him compared to what Loki _would_ inevitably do to him. It didn't matter that none of this meant anything. “I refuse, Maya.”

She sighed, and hit a button—an intercom. It crackled with static. “You win, Tem. He’s yours.”

“ _I did tell you so,”_ Tem replied. The sound quality was terrible, but Tony could still hear the amusement in his voice. The speaker on the other side clicked off.

“You’ve still got about a minute to change your mind,” Maya said, meeting his gaze and holding it.

He stared back at her. He refused. He refused. He refused. He—

The door rattled, the bar lifting on the other side, and it swung open. A pair of honest-to-god _ninjas_ swept inside—dressed all in black, fucking _swordhilts_ showing over their shoulders, as if they were about to go all samurai on him at any moment. Tony blinked, and nearly broke into hysterical laughter.

They moved like Steve did, or Natasha: perfect poise and balance. Damn _._ There went that idea.

“Come,” said one, with some accent that Tony couldn’t properly identify.

“Yeah, I’ll just... do that.” Tony stood, clutching the blanket around him with one hand.

Ninja One led the way out; Ninja Two brought up the rear, and the feeling of eyes centred on his back made him want to make a break for it, try his luck. The outside hallway was more stone and concrete, surprise, surprise. The door shut behind them, but Tony noticed that it wasn’t re-barred. So. Whatever power structure they had here, Maya hadn’t been demoted to prisoner.

Tem was waiting for them in the hall. He was dressed more like One and Two than like Maya: warrior, not scientist, except for the eye-glasses perched incongruously on his long nose. Considering the rest of what he was wearing—sword, but his had golden thread woven in the wrappings on the hilt, loose pants, a tunic of a rather non-Western style, and boots that vaguely resembled sandals—Tony would have expected he get contacts, if only to _fit in_.

Swords. Really? Modern forces, no matter where the fuck they were from, did not use _swords_. On the other hand... Tem’s rings gleamed on each of his fingers and thumb, deadly cracker-jack box jewellery. Tem was no more an ordinary guy than Steve was.

“Is this the part where you make me commit seppuku?” Tony asked.

Tem smiled and turned his back, walking away. Ninja Two gave Tony a shove between the shoulder-blades when he didn’t immediately follow. For the hell of it, Tony stumbled more than he had to, but neither of them moved to grab him.

“No, Tony,” Tem said, his voice carrying back easily. “This is not that point yet. There remain many moments before then, in which you may well decide to become more cooperative.”

Tony lost the battle, and laughed. Chuckles echoed off the stone walls, as they turned past other corridors—he marked the twists; they weren’t bothering to blind-fold him, which was probably a bad sign—and down subsequent, short flights of stairs. It took him a good minute—nine flights—to get himself back under control enough to speak. “You know I’ve _done_ this before, right? Seriously. Come on, Tem. In what world does this end well for you?”

“Ah, Tony,” Tem sighed. “If you’d work _with_ us, it would go easier for you.”

“No.”

 _Yes_.

_Nononononono—_

He couldn’t break _that_ easily. If he was going to break. If Plan A didn’t work. Tem wouldn’t believe him if he broke yet. Would he? Past history—fuck, he _wanted_ to—

Three more flights, and the smell of ozone lingered in the air. Ninja One darted ahead to open a pair of double doors—both at once, they were really going for the dramatic, here—and... sweep the inside, or something. Tony didn’t pay much attention. His focus was on Tem, specifically on the movement of Tem’s fingers. If he could grab the right ring, and if the reports were correct in assuming the rings were the source of Tem’s powers, then he might be able to get the damn collar off his neck.

_That can be Plan B._

The double doors led into a much larger hall, one that could be considered a _hall_ in the old-fashioned sense. Windows set at a second-story level let in daylight, illuminating the place's features: tapestries draped over stone walls, a throne-like chair at one end. There were at least four other doors that Tony could see, and three of them were open. It was the best chance he was going to get. He twisted one bit of wire between the two control contacts on the ICG, managing somehow not to fumble and drop both it and the arc reactor, and vanished.

Ninja Two lunged forward to grab at where he’d been, evidently not assuming teleportation— _shame_ —and Tony threw himself to the side, dropping the blanket, which appeared out of his invisibility field as if from nowhere, fluttering to the ground and revealing the pattern of his movements. He rolled to his feet and switched directions, darting not for the closest open door but for one nearer the throne.

Blinding light raced across his vision and electricity flooded his brain. His own spasming muscles threw him into the throne’s dais as thunder shook the room. The wire on the ICG bit into his palm hard enough to draw blood; he couldn’t unclench his fingers, he couldn’t make his muscles do damn _shit_.

_Air—_

The spasms in his arms and legs began to fade, but his lungs still wouldn’t obey. Desperately, Tony choked for air, but there was no code to rewrite, here, no force of will that could overcome nerve connections that weren’t fucking _working_. _Air, oh god, please—_ and his lungs kicked into sudden obedience, sucking in air so quick that he nearly choked on his own spit. He coughed, and curled inward, painfully.

Rough, quick hands grabbed at his head, then got hold of his shirt. Tony tried to move away, but all his muscles were like limp noodles. It was Tem, he realized, managing to get his eyes to focus briefly. Ninjas One and Two, and a Three and Four that had appeared from somewhere, were also down and twitching on the floor, but Tem was fine. Whatever Tem had done—it had to have been Tem, with those goddamned _rings_ —he'd let it hit everyone else in the room, invisible and friendly alike. Ruthless of him. Tony had time to figure out that much, and then Tem shook him hard enough to practically give him a concussion. The ICG slipped from his fingers—now starting to go numb—before he could stop it, and the world flickered back into normal view as he dropped away from the invisibility field. If it made a noise when it connected with the floor, Tony couldn’t hear it. His ears were still ringing from being caught in sheet lightning.

Tem’s mouth was moving. Tony stared at it, trying to understand the words—they were probably words—but extremis was shut down and half his vision kept greying out at random-but-rapid intervals. It didn’t seem like he was expected to understand, though. Without pausing to wait for a reply to whatever-it-was, Tem yanked him around, twisting his hand to get a better grip on Tony’s shirt, and started half-dragging, half-carrying him one-handed toward a different door than the one Tony had been trying to make his break for. Give the guy credit—his hair might be grey, but he didn’t seem to have any trouble hauling Tony around.

Sound started coming back as Tem dragged him down a steeper flight of stairs than any of the previous. So did limb control—he flailed in Tem’s grip, and when they got to the bottom of the stairwell, Tem dumped him unceremoniously on his ass. “I’ve upped the feedback on the collar,” Tem informed him. He sounded like he was speaking underwater. “Try reaching for extremis again, and you’ll be out before you realize it.”

Tem thought the invisibility trick was extremis. _How_ did he think it was...? Unless... the control circuit for the ICG; Tony had blood dripping down his hand—he was pretty sure—from how hard he’d crushed the wire into it. Had it gotten caught in the contacts? In which case there was an invisible reactor sitting upstairs, just waiting for somebody to stumble over it...

 _Maybe you can use it for part of Plan C,_ he thought dazedly.

With a great deal more effort than was really warranted for such a manoeuvre, Tony climbed to his feet, leaning heavily against the wall. There was, he suddenly noticed, another pair of ninjas following them. Where had— _no, stupid question_. How many fucking ninjas did Tem _have_?

Apparently, he had enough to be able to get away with snapping his fingers at these two—or, wait, was that putting effect ahead of cause? Tony hadn’t managed to sort out the relationship there before Ninjas Five and Six each grabbed one of his arms and dragged him forward, off-balance. He yelped as toes bent back on themselves in ways that toes were not meant to bend, but they took no notice, dragging him at a brisk clip after Tem, who turned and continued leading them onward and downward.

His mental map had gone all shaky. Lightning—and the after-effects, which were making it difficult to really see his environment. His mind kept overlaying the stone masonry with a cruder kind of stone, unworked...

The problem with reminding himself that that wasn’t real was being faced with the fact that the present _was_.

_Probably._

That wasn’t a comforting thought either.

By the time his sight returned to normal, every last one of his toes was bruised if not sprained, and they’d probably lost at least a hundred metres of elevation. They turned down a last steep set of stairs and were confronted with a pair of double doors, open and waiting. The ninjas stopped, right outside, but Tem kept going on, into a darkened hall beyond. “Close the doors behind us.” His voice echoed, with enough layers to hint at the hall’s true size. Hall? Cave? Cavern?

Five and Six threw Tony forward. He had enough presence of mind to fall properly, rolling to absorb the impact, but by the time he staggered to his feet— _ow_ —the doors were shut. The sound of a heavy bar being placed across them was audible from this side.

The only light in the hall was from two torches, one on either side of the doors. Tony squinted, bringing up a hand to block their flames: trying to look around with them in direct view was futile. Without the flames killing his night vision, he could make out some of the enormous tiles on the floor... was that a tapestry on the wall? As his vision adjusted, he could see that if it ever had been, it was now only rags.

“Why the medieval effects?” Tony asked. His voice was hoarse, his throat sorer than it had been when he’d woken up. Side-effect of electrocution, he supposed.

The voice that answered wasn’t Tem’s. It wasn’t human at all. It was a choir speaking in unison, echoing off of every flattened surface in the hall, but half the choir had pitched their voices to achieve discord with the other half, a hundred flat notes. “In fire there is more than mere illumination. Mandarin... why does he yet speak?”

Very slowly, heart beating very rapidly, Tony shifted his gaze to stare into the darkness.

“He might yet say something of use.” Tem’s voice floated out of the shadows, and then there was a _hsst_ and a gout of flame, arcing about the room—aligning perfectly to ignite the torches along each wall. Each torch burned bright and hot, white fire reaching a foot or more in height, and had a twin reaching down from the ceiling, which Tony could now see was mirrored. Between the torches and their reflections, the cavernous hall was illuminated.

It was a hall, not a cave: the walls were straight and rectangular. It was at least thirty metres long, and that was just what Tony could see of it, before the immense bulk of scales that had to be ‘Fin’ rose up so high and wide that Tony couldn’t see past. Fin’s head alone was three metres wide, and he had fin-like fans—ha, fin—like some of the dragons in Maklu, or before Maklu, had had. In the torchlight his scales were a darker green than the images from the Valley of Spirits fight had made them seem.

Looking tiny beside his vastness was a workstation sized for a human, and an oblong, polished table that Tony would have wagered money wasn’t actually a table, if he’d had money anymore. Tem went over to the workstation and booted it up. The light from the screens reflected in Fin’s eyes, little pale rectangles that didn’t quite fit with the images of torches. Then Fin began to uncoil, snaking his head out over the entire set-up, the torches winking away as he moved ahead of them—Tony found himself with his back pressed against the door, and there was nowhere further to go.

“We’d learn more if I ate him, my lord.”

 _Shit. Shit. Work this out—loyalty or technology?_ It was impossible to tell from Fin’s tone, not when he had a hundred of them. But Tem did have those rings...

“No,” said Tem, but indulgently. “Not so long as he still has any Makluan links in him.”

Fin hissed. Most of him hissed, that was. Some of the higher pitches in his voice...s... chittered, instead. “In him they would be corrupted... no longer a threat. The pure links are dangerous. The ones in him aren’t.” His breath gusted over Tony, a warm wind stinking of rotten meat and stomach acid.

Tony couldn’t help it; his body heaved and he retched, although nothing came up. The rough wood of the doors caught on his shirt and made little rips in the cloth as he slid down it. At last he managed to bite his shirt-sleeve—and, god, it was second-hand but it was still the better option—and get his insides to desist. He covered the rest of his face with his other arm, but he could still feel the humidity of that foul breath on his skin, soaking in...

“As a last resort, we may consider it,” Tem conceded.

_I can’t—_

_Please—_

_I'm going to die screaming anyway, I can't—_

“Jesus Christ, I’ll help you,” Tony swore—he had to turn his face to the side to make the words heard; he couldn’t— _couldn’t_ —just lower his arms. “I swear to god, I will, what the fuck do you want to know? I’ll tell you—Christ, okay, just—”

Fin _laughed_ , the joyous roar of a mob watching a public execution; Tony felt spittle hit his hands, and he recoiled, wanting nothing more than to scrub it _off,_ _off_ , but the door remained shut behind him and there was nowhere to go and it was _in his skin_ —

“Well, well,” said Tem’s voice, much nearer now. “Tony Stark does have limits, after all.” He sounded amused. “Or so he would have us believe. What did you promise your captors in Afghanistan, Tony?”

“No! This isn’t—I—whatever you—no, I’m not lying—” It was on his skin, probably in his hair—every breath he took, he drew it into his lungs, and he wanted the armour, _needed_ it, it and the air filtration systems—

He reached for it, and lightning burst in his head, down from his neck into his body.

This time, the world went dark.


	13. Weapons of Words: 3.2

“The last time I got lost in another reality, Reed thought it would take months to figure out where I’d come from,” Steve remarked, looking at the portal that Toni had somehow managed to build inside a couple of hours. He decided not to mention that it had taken SHIELD weeks to put together their own portals.

“What, you do this often?”

Steve grimaced. Maybe he shouldn’t have brought that up. “I have bad luck.”

“Heh. Our Reed would probably have had you back in half the time it took me—there’s some things extremis can’t compensate for, and multiversal experience is one of them—but we really do need him on the Thanos problem more. No offence.”

“None taken,” said Steve softly. The words of the Guardian, recalled freshly to mind again, chilled him. _Fifty-six worlds._ Steve had seen what Thanos had done to one world, and that had been bad enough. Trying to comprehend devastation on that scale... he couldn’t quite manage it, and wasn’t sure whether or not to be grateful for that.

“We do have a request,” said Other-Steve, and then held up a hand. “It _is_ a request, before you think otherwise—we owe you for letting us know about Thanos.”

“The Guardians would have gotten around to it sooner or later,” called Toni. Her head was stuck under part of the machine.

“The Guardians still think Earth’s a backwater, and treat us like it. No, we owe you. But this SWORD idea of yours also has merit. We’d like to come with you—see your world for ourselves, and set up the foundations for a more concrete alliance against Thanos.”

“The WSC would pitch a fit,” said Jane, looking up from where she was peering over—or, rather, sort of under—Tony’s shoulder. She didn’t sound at all bothered by the idea of pissing off the Council.

“Sometimes it’s easier to present them with _fait accompli.”_

“Exactly,” said Steve’s counterpart, and they broke into grins at the same time. It was like looking in a mirror, almost. Other-him was older, with very faint lines about the eyes—Toni had implied that he didn’t have a healing factor—but not as much as the first version of himself he’d met.

Somehow, he hoped he wound up like this one. He seemed happy. Not that Steve was unhappy—although there hadn’t been a lot to be happy about in the past few months—but... there had been the Depression, and then the War, and it sometimes seemed like life was one constant struggle. His other self... didn’t seem to be struggling. He moved too easily for that. It was like there was some weight on Steve’s shoulders that his counterpart had managed to slip free of.

He just hoped that what he was about to ask—what he _had_ to ask—wasn’t about to prove him wrong.

“I need to know about extremis first.”

Toni pulled herself out and back to standing position. “What about it?” Something in her eyes had closed off with wariness.

“Did it kill anyone?”

“Yes. Two. Well, three. The last was indirect. I had to kill him myself—he was a nightmare,” said Toni, as blunt as any soldier. “He killed twenty-seven people before I could stop him, so you could say it was thirty. And Maya’s doing life now, so call it thirty-one.”

Thirty-one. _Lord._ It was wrong to think—lives couldn’t be counted and weighed, they didn’t tally against each other, but Lord, _only_ thirty-one... Steve looked at Other-Steve and caught the frown on his face.

“I had to ask,” said Steve.

“Why?”

“In ours it killed millions.”

Toni’s face could have been carved of stone; Other-Steve’s breath whistled in through his teeth. “God.”

“God, your world isn’t fair,” said Jane quietly. She wasn’t looking at any of them. “None of the screw-ups, tech _years_ ahead of ours—” She thumped one of the support pillars for Toni’s portal machine. “And I’m a nurse.”

“There’s nothing wrong with nurses,” Steve protested, and abruptly found himself on the end of razor-edged glares from both Jane and, surprisingly, Toni. He glared right back. “It’s a tough job and—”

“Drop it,” said Other-Steve. “Now isn’t the time. Is Toni having extremis going to cause problems with your world’s authorities?”

“If it’s not contagious, no,” said Steve, turning aside. “Tony has it, too. But if it interacts weirdly...”

Toni raised her hands, palms turned toward each other—Iron Man with palms facing straight-out was a threat; this deliberately wasn’t. “I’m polite enough to keep out of your systems. And I can keep another extremis user out of mine.”

“It’s not the same extremis. It’s based on Makluan technology.”

“Mak—the _Mandarin_ ,” Toni hissed, her eyes lighting up with realization. “Then he succeeded in your world—that explains the body-count.”

“Tony was away, at the time,” Steve said carefully. “Off world.”

“And you only have a few superheroes—no speedsters, no technopaths... damn. I’m sorry for your losses, Captain,” said Toni, and the hostility from earlier was gone completely.

_So am I._

“You might be looked at with suspicion. Our Tony... extremis wasn’t good. And he was doing questionable things.”

“I can’t say I’ve never done any of those,” said Toni. Her voice and her expression were scrupulously neutral, but her eyes were shadowed, in the same way that Tony’s got, sometimes.

“He’s been having difficulty with extremis. There’s no one else to fix it. If you might know...”

“I’ll help if I can. And if time allows.”

“Tha-at would be a good thing,” muttered Jane under her breath, not quite low enough for superhuman hearing to miss it.

“We’ll be careful,” said Other-Steve. “We want— _need_ —to forge an alliance between our worlds. But Toni’s not the same person as your Tony.”

“I know.”

“The boobs'll give it away, darling,” said Toni, and Other-Steve reached over, absently grabbing her hand and giving it a small squeeze. She squeezed back, then reached with one hand to the giant red lever attached to the side of the portal device, and with the other for her helmet.

“ _We ready?”_ This Iron Man’s voice was much more mechanized than Tony’s, robotic to the point that it sounded neither female nor male.

“Um,” said Jane, scurrying over to stand closer to Steve and Other-Steve, grabbing some papers as she went. “Okay, ready.”

“Ready,” said Other-Steve, and Toni pulled the lever.

It wasn’t like any of Tony’s portals, or Loki’s insane method of travel—instead it was just like blinking, one half-instant of darkness and then the realization that the world was different. Noise arrived a moment later: computer fans whirring, the click of keys and mice, agents talking into headsets, the underlying roar of the Helicarrier’s engines. But what triggered the most sense-memory was the dry feel and smell of artificially pressurized air. There was an instant where all talking and clicking stopped, and Steve moved without thought, a hand on Jane’s back pushing her down and into the centre of a triangle with himself, his other self, and Iron Man protectively around her. Around them safeties clicked off and techs ducked out of sight.

“Friendly!” Steve shouted. “We’re friendly! Don’t shoot!”

“Hold your fire!” a thankfully familiar voice called out, getting better results than Steve had—granted, nobody _had_ shot him, but at this second command fingers eased off triggers and returned to guards. Steve felt himself relax just a little bit as he turned to face Hill.

“Deputy Director.”

“Captain Rogers.” Hill’s expression was sour. She holstered her own gun, stepped out from the console that she’d taken partial cover at, and looked between Steve and Other-Steve. “And Captain Rogers, I see.”

“Commander, actually,” said Other-Steve. His tone was just a _bit_ too mild.

“Found a way back home,” said Steve, lowering his shield and trusting, or perhaps hoping, that Hill would do them the same courtesy. “Thought we’d bring guests.”

“ _Hi,”_ said Toni in her armour’s flattened voice.

Hill looked like she had a headache, but she turned it on her subordinates. “Lower weapons,” she ordered. “Notify the Director and get Banner up here _immediately_.” Her hand rose to her comm. “Romanoff—”

“I’m here,” said Natasha, materializing out of nowhere. “Steve, I think I can honestly say I’m sorry I ever doubted you.” Her eyes slid over Jane, then Other-Steve and Toni, and she raised an eyebrow. “Commander America and Iron Man, eh?”

“ _Commander Rogers, Captain America. Don’t ask. And yes, Iron Man,”_ said Toni, reaching up and taking the helmet off, “although less literally than I’m given to understand is the case in your world.”

For a single moment, Natasha’s face lit up with unholy glee. Hill’s eyebrows attempted to crawl up into her hair-line, and the bridge went semi-silent again.

“Ma’am, Banner wants to know if he can portal aboard?” a tech asked nervously, breaking the quiet.

“He has a go,” said Hill, turning back, all professionalism once more.

“He can do that?” Steve asked, at the same time as Jane demanded, “He solved the short-distance complex? _How?_ ”

“You were gone awhile.”

“We were gone a _day_ —”

“I thought you said our time-streams match,” Other-Steve said to Toni, who held out her wrist. A blinking panel popped up from the armour’s gauntlet.

“They do.”

“But some of that time we were with you-know-who,” said Steve, his stomach sinking. They’d been gone awhile. The last time he’d gone no time at all had passed. He hadn’t thought it would work the other way. “Natasha. How long?”

“Five weeks.”

“Definitely not while you were with us,” Toni said firmly.

Five _weeks_ , Lord—“I need to see Tony.”

The last lingering amusement in Natasha’s expression died. “That’s a problem.”

“What happened?”

“We went after you.” Steve almost asked, _‘How?’_ , but Natasha was already explaining. “Thor came—he’d seen what had happened. He had a way to track Loki—you don’t have to worry about the names, we’ve updated the AEDs with Dr. Foster’s work. Tony had portable portal device, and he and I and Thor went after you. But we got separated. Thor got sent back to Asgard. I got back here with some help of my own.” Her eyes slid over once again to Toni and Other-Steve, both of whom were listening intently. “Tony hasn’t.”

“But he has a portal device—”

“Yes.”

_Something's happened to him._

There was a _crack_ as air displaced, and everyone whirled—two shields rose, Iron Man’s repulsors’ whined, and at least thirty guns cleared their holsters, pointed at the new target that had just teleported onto the bridge with a flash of blue light.

Bruce held up his hands. “Uh. I did ask permission.” He tilted his head, looking at Toni, who hadn’t had time to put her helmet back on. “Good grief.”

“You solved the short transfer complex,” said Jane, sounding dazed. She looked a bit dazed—shocky. A civilian, yanked out of her everyday life, and now deposited back into reality.

“Um, yeah.”

“Equations. _Now._ ”

“Later,” said Hill, voice firm but not unkind. Steve saw her flash hand signs to one of the other agents for medics. “The Director’s jet will be here in fifteen. You’re all going to the med-bay for a nice round of tests and then thorough debriefing. Or whatever it is you’re here for,” she added, nodding to Toni and Other-Steve.

They glanced at each other and shrugged simultaneously. “Better kept in closed conferences,” Other-Steve said courteously.

Right. Probably a good idea. Steve should have suggested it from the start.

God, where the hell was Tony?

 

* * *

 

Tony woke to find that he was lying flat on his back again, although this time he seemed to have been laid out on the stone floor rather than on a cot. That felt like a step down.

His skin felt gummy. Dry-ish, but still... unclean. Probably crawling with alien bacteria; mouths were fucking filthy. He shuddered.

 _Keep it under control, keep your brain under fucking control_. His thoughts weren't drowning in static and he had no excuse for trying to make them. Plan. He’d had a plan—right, and that had gone peachily. Plan B had been trying to do the same damn thing he’d done in Afghanistan, except maybe he’d started out a bit too well, here. And not well enough: Tem had turned him down. _Fuck_.

Plan C was sitting upstairs—hopefully. If no one had tripped over it yet. Plan D should probably include a sub-plan to get upstairs to retrieve it.

“The annoying thing about turning up the feedback on your collar,” said Tem, “is that it means I’ll have to keep waiting for you to wake up. That’s a problem.”

Tony boosted himself up and into a sitting position, with effort. Moving hurt. _That’s what happens when you get electrocuted twice in fifteen minutes._

“I said I’d... help you,” he said. Sort of. It might have come out a bit garbled; the sounds didn’t seem quite _right_ to his ears.

_Oh, christ, brain-damage._

How was his heart still working? As heavy as those shocks had been, he was getting off remarkably easy—

_Don’t think about it don’t think about it—_

—if he wasn’t in serious danger of dying by now. Body re-written to be decades younger or not, without extremis he was _human_ , still.

_Unless extremis isn’t entirely suppressed..._

He clung to that thought as the darkness above him moved, and he caught sight of Fin’s enormous black eyes watching him. He looked away, only to see that the eyes were reflected in the surface he was sitting on... that strange, oblong table he’d seen earlier.

_Jesus fuck._

“You haven’t even heard what I’m trying to do, Tony,” said Tem. There were several clicks, echoing off of the walls and distorted so that it took a moment for Tony to realize that they were mouse-clicks: right, Tem was sitting at a workstation, his back to Tony, his attention on the screens before him. Tony squinted. The text was not quite big enough for somebody with merely above-average vision to read it from the distance he was at. Steve would have been able to read it.

_Don’t think about it—_

“What do you want, then?” Tony asked, and took it as a triumph when his voice didn’t crack in the middle.

Tem swivelled around. Apparently swivel chairs were good enough for the modern ninja, although Tony noticed he didn’t try to lean back in it. Not with the sword. “I want to adapt it, of course. Take what you have... extremis, perfected... and give it to the rest of the world.”

Carefully, Tony slid himself backward, toward the edge of the table, away from Fin’s unblinking gaze. “Um. Look. What I’ve got isn't really extremis. It’s Makluan. Which you have an expert in, here...”

“Lie back down,” said Tem, and an invisible force shoved Tony back down to the table, flat on his back.

No, not invisible. His own muscles, rather, tensing due to someone else’s command.

“Makluan links aren’t designed for human use, and they don’t work for humans,” Tem went on, as if he hadn’t just walked into Tony’s head and made him roll over like a fucking trained chihuahua. “Fin and I tried to modify it for years with limited success—Maklu frowns on giving their secrets away to outsiders, of course. Now, I thought that taking Maya’s work as a base could work, considering she nearly cracked extremis for humans years ago, but you seem to have gone and done it the original way: Makluan code corrected for the human brain. You must have done something to impress them. I had no idea you even knew of Maklu’s existence.” He sounded fascinated.

He also sounded more than a bit out of the loop. That was good. Tony didn’t really need his enemies to be working together. He was plenty screwed with things as they were right now.

“I’m pretty sure it was an accident on their part,” he managed to get out. His lungs were refusing to breathe in all the way. Were his shirts denting inward over the hole where the reactor should have been? Had they noticed it was missing yet?

_The only reason they wouldn’t care... was if they had a better power source already._

He might’ve thought it Makluan technology, except apparently Fin, for all that he was Makluan, wasn’t a great enough mind to be able to figure out the nanites. Had he failed Makluan Reactors 101 as well? Or was it just that those fucking rings Tem was wearing were a much _better_ source of energy? That begged the question of how much energy they _could_ output. Thor had gone up against him in that contest and tied him, but that might have come down to a question of durability.

“Accident, eh? That isn’t as surprising as I might wish.” Tem sighed. “They’re too damn insular. Setting themselves up as gods on the mountains... no, granting godly gifts to a mortal by _accident_ doesn’t surprise me.”

Tem was suddenly in Tony’s field of view—he’d moved without making a sound. Gold star for the ninja outfit. Tony would have flinched, but all of his muscles were strung too tight and weighed down by an invisible command.

“Why?” Tony gasped.

“They’re not gods, Tony. Neither are you. They’re just what we _can_ be, what we should be. And, with the help of extremis, perfected... what we _will_ be. The transcendence of the human race. Isn’t that a worthy goal?”

“Twenty million people.” His heart was high in his throat.

He tried not to think about offering to help, again. Tem had made it clear that it wouldn’t do a damn thing—

_You don’t mean it—you don’t—_

“Haven’t you weighed that price? The weak will fall. The strong will become something more.”

_Right, you’re fucking insane._

Christ, he really knew how to pick ‘em, didn’t he?

“It is complete, my lord,” said Fin, and Tony felt his eyes roll back in his head as he tried with all his power to cringe away from that fetid breath and went absolutely nowhere. The words after were nearly unintelligible above the rush of blood in his ears. “—table—prepared.”

“Good,” said Tem, and something clicked on either side of Tony’s neck... attaching to the collar? Tony rolled his eyes as far to the side as he could, and, perhaps through some sort of inattention on Tem’s part, managed to turn his head perhaps ten degrees to the right. On the far edge of his vision, he could just barely see a fibre cable dropping away from the table. Human-made.

_Wait, does that mean—_

Tem clamped his hands on either side of Tony’s face—palms over ears, thumbs just beneath his eye sockets with a punishing grip, fingers curled around beneath his jaw. One of the rings on his left hand was burning hot, too hot; it might actually have been searing into Tony’s skin. Any unwilling sound he might have made, however, was crushed beneath an entirely different will.

Stars burst in his vision—he had the mental image of Tem’s thumb slipping beneath the pressure, gouging into his eyeball, popping it to release the viscous fluid within... human eyes were so frail. His had nanites floating in them, able to enhance any image he saw, but what was the use of that if they were all just so much dead metal? He should have just gone the fully cybernetic route instead. The schematics for it swum in his head—he hadn’t done that sort of designing in ages. Months, at least. Extremis was more efficient—

Code flickered into view—and then there was electric pain, again, dancing up and down his skin. The hands on his face gripped harder and the code drifted sideways—

But that meant it was real. This was extremis’ code-viewer.

_Not entirely suppressed..._

Arcs of current kept flashing across his vision, disrupting his view of the code. He was pretty sure those were imagined, or hallucinated; neither he nor Tem should have survived if he was actually _seeing_ current arcs like that. The blinding flashes made it a struggle to concentrate long enough to even try rewriting any of the characters. This was... external-input extremis—the type of language that they’d used when he’d been working on it with Maya and Tem, for six long months. It should have looked different, here, inside his head—

It changed, before he could manage to change it himself, and became a different segment of code entirely, the coding for logic-arrays.

 _Oh_ , he thought. So that was what Tem and Fin were doing. Of course. Tem wanted the key to human enhancement, and that couldn’t be found solely in the extremis nanites that formed his armour, his clothes. Those were specialized in their own way—to work perfectly with the ones that he kept inside himself, yes, but they had a different purpose.

 _Not everyone’s a computer programmer,_ he wanted to say. _Jesus, look at what you’re doing to me_ right now _. This won’t elevate anyone. I took a chance because I had to—you don’t know what—_

More code, this time for emotions. Fear. His own greatest weakness, written on the inside of his eyeballs for his enemies to see.

And that made three-out-of-three, which meant that what he was thinking about was definitely having some sort of impact on whatever search they were doing.

 _Hands_ , he thought. _Bones, re-growth_ —he’d dwelt on that in agonizing length, at one point. Now he relived what he’d done to fix it and all those tiny bone shards. Tendons, too, and nerves; improved tactile feedback. Schematics crawled over his vision. He didn’t have complete control over them—he tried thinking about holographic schematics, but these stayed annoyingly two-dimensional.

“Extremis, Tony,” said Tem, his voice low and strangely empty of any threat. “Show me.”

Tony thought about code. In the other world, before everything had gone wrong, he’d written a masterpiece—a virus hidden in a message hidden in a virus. He’d set it loose to grow and spread, an innocuous little bit of code that did absolutely nothing in any place more technologically advanced than Earth—because everywhere more advanced than Earth, which seemed to be damned near everywhere, had the anti-virus. And after nearly shutting off Manhattan, Tony had made sure that all of his own tech had the anti-virus, too. By now it was ubiquitous throughout SHIELD’s tech as well, but that was because they kept stealing his ideas—on those occasions where he didn’t just hand them over—or because he’d added it himself. It wasn’t because anyone else _knew_ about it. With everything else fucking up, SHIELD had never asked him about it.

Tony had thought that the shock-collar had to be pure extremis, but a fibre hookup said that it wasn’t. That meant that there was a chance that if he set this off, some part of the collar might fall apart. If Tem wasn’t using something adapted from Tony’s own designs—if he’d unwittingly left that oh-so-crucial bit of anti-virus out—

Code scrolled past his eyeballs too fast for the human eye to read, and without extremis, he didn’t try to parse it. It was all from his own head anyway. Going that fast meant that Tem wouldn’t be able to read it, either—he’d need to figure out what it was later. There was a moment at the end where it paused, and then Tony started thinking about the patch he’d written to take apart the zombies. Being fed data—receiving _cooperation_ —seemed to take up some part of Tem’s concentration. Tony thought he could probably move a fingertip.

He only needed one, to sketch tiny three-dimensional runes in the air.

The last down-stroke connected with the point he’d started from, and the light from the computer screens winked out. Electricity crackled over his skin as the world opened up. The ceiling peeled back, exposing the sky above—five satellites overhead connecting to another two thousand six hundred twenty-one in orbit. GPS found his location as he screamed, muscles spasming—extremis stealing the power from the half-broken shock-collar and _feeding_ on it the way it couldn’t from the empty hole in his chest.

_Where the fuck is my armour?_

Awareness of it danced at the edge of his brain. He threw more of his stolen power into it, and the part of the collar that was still working switched off as a component overloaded. Tem’s fingers began to tighten on his skull with inhuman strength—but perfectly human speed: Tem was only now beginning to react to the loss of power, and from the point of view of extremis hopped up on terror, human reaction times were as slow as molasses.

All the time that he had remaining—before Tem crushed his skull barehanded—stretched out before him, a long and endless road. Some part of him was aware that it was an illusion: panic and adrenaline made time seem to slow but slowed the brain as well. Lightning crackled again, directly from one of Tem’s rings this time, a spark stretching out over Tony’s face. The full force of its power built—he could feel the rising potential of it, too much for extremis to be able to shunt.

He had to get his armour first. The very front edge of the lightning wave, the beginning of the rise, he fed straight into the nanites—burning tissue as it went—and he reached for the armour, the sense of it crystallizing in his mind as pumped more power into the sensors. It was there—goddamned _buried_ , but if only he could reach—

_Not gonna make it._

But he could try—

_Plan E — Plan Z —_

Use all the power to call his armour and probably pass out before it got to him—but possibly wake up safe inside it, ready to kick ass. Or divert some of the power to communications, to the sky and satellites above, and hope like fuck. He knew what the odds were—what they were, so long as he could trust the people he was reaching out to wouldn't betray him—

_steve would NOT have used it!_

Steve, who'd told him that he had done _enough_ —that he could pass the torch and it would be in safe hands. Natasha, who’d come with him, jumped into the unknown to keep an eye on him... and to watch out for him, even when she couldn’t still follow. Gaea, whose assurances of safety were backed by nothing more than instinct, but she hadn’t let him down, and now he could think enough to realize how completely fucked they all were and still think _past_ that.

None of them were on Earth right now.

But—Bruce was. Angry and yet still watching out for him. Clint. Rhodey, off in Japan but still answering emails. Pepper—despite everything, she _wanted_ in, wanted to help.

He couldn't do this alone. He couldn't do this at _all—_ none of them could—but he might as well give Steve the satisfaction of cooperation before they all died.

The impulse wave rose and even with extremis he was out of time to think, to weigh the odds a third time. His thoughts scrambled, split a thousand ways, and arrived at SHIELD’s communication banks with the virus scattering in his wake to rip through every piece of unprotected tech it could reach. Alarms blared, sirens screamed—no time for subtlety, no time for tricks. He lit up every console he could find with a map and all the data he had. Bits of him that had gotten lost watched from the cameras and mics as agents’ eyes began to widen—human speed, human reactions; most people hadn’t even registered the change before the current wave roared past what extremis could shunt, and Tony’s vision turned to bright, bright, white.

 

* * *

 

A high-pitched siren wailed, breaking all conversation, as every screen in the conference room lit up at once, including a number of surfaces that Steve hadn’t realized were screens. Everyone’s hands went up to cover their ears, everyone except Toni, whose eyes rolled up in her head. Steve lunged to catch her as she collapsed. In his peripheral vision, he recognized the image that was playing on all the screens as imagery from a satellite.

“Get medical!” Steve shouted to be heard. The siren cut off just as abruptly as it had started and he wound up shouting it to the entire room—and the bridge, as the conference room door was shoved open by alarmed agents. That was just fine with him. He laid Toni out and had just enough time to determine that she wasn’t breathing before his counterpart reached them both. “She’s not breathing!”

“Armour override: Steve Rogers, 34-44-54-64,” Other-Steve barked, but nothing happened. He swore, and went straight to rescue breathing.

Bruce had lunged forward, too. Now he was staring helplessly at the armour, locking Toni away from aid. Hill was on the comm with Medical. Fury was barking orders at the techs to backtrack the signal and figure out what had just been dumped into the Helicarrier’s systems.

“—a team of engineers down there,” Hill finished, and reported to Fury, “Sir, half of Medical’s secured equipment just went offline—”

Steve met Bruce’s eyes over Tony’s form. “You can get her out of the armour.”

Bruce shook his head. “This isn’t—this isn’t a good situation for it, there’d need to be something else to smash—

“—call for help, Director, it was signed by Tony Stark!”

“We’ve got trouble—satellites are going out of sync—”

Bruce’s eyes were green.

“Five maydays—twelve—it’s not just local, we have aircraft off course over the entire hemisphere, civilian—”

“Medical at HQ is reporting the exact same thing, everything electronic just shut off—”

“Captain, if Stark’s seeded a virus through our systems, you better be prepared to drop him,” growled Fury.

A virus. Steve’s eyes widened. _Oh, no. He didn’t. He said he’d ensured everything was protected against it!_

But could he have overlooked secured systems that he had no particular reason to access? Extremis was nearly impossible to secure against, but although Tony had described the virus he’d used to take down ULTRON as ‘sticky’, had he ever explicitly, or even implicitly, said that the anti-virus was the same? Or had Steve just jumped to conclusions?

There was no time to waste doubting it—“Wait,” Steve told Bruce, and backed up enough. When Tony had sketched the anti-trigger for Natasha in New Orleans, he’d done it backward; Steve replayed it and fit the motions back together. In his mind’s eye, he followed Tony’s movements exactly, trying to mimic the timing as closely as possible. Better to get it on the first try, then rush through it and find out that the timing was important—

Toni gasped, her eyes flying open, and Other-Steve broke away—and then back, his hands on either side of her face, looking into her eyes and murmuring, “Tasha, Tasha...”

“—control back to the craft—”

“They all just rebooted?”

“—five recovered—that last one is not pulling up, it’s making an emergency ocean landing. We’re the closest to assist with rescue efforts—”

“What the _hell_ was that, Captain?” growled Fury.

Steve looked up to meet his eyes. There was something distinctly disadvantaging about kneeling while Nick Fury loomed over him, so he jumped to his feet. “That was Tony, sir. And he needs our help.” He nodded toward the tech who had come up with the identifying report, who was nearly bouncing on her toes.

 _Please, please don’t have killed any innocents._ If medical equipment had gone offline... back in ULTRON’s world, people with pacemakers had been fine. Why the hell couldn’t it be the same here?

“He just gave us the location of the Mandarin,” said the tech excitedly. “And, uh, is apparently a prisoner in his evil lair, Stark's words—sir, _we have the Mandarin’s current location!_ ”

“Scramble teams,” Fury ordered, and acknowledgements coming over the line from Clint and Natasha let Steve know which channel he’d said that on. “You all right, Ms. Stark?”

“What the hell was that?” said Other-Steve and Toni, practically on top of each other.

They shared a glance, and Toni added, “I want a copy of it, whatever it was.”

She was fine, thank God. Steve tapped his own comm over to the New York labs. Bruce was up here, but Foster had returned surface-side an hour ago. Was that enough time for her to figure out how Bruce had turned the portal into a teleporter? If not, surely Bruce’s techs would be able to run the process— _please—_ “This is Captain Rogers, I need Dr. Foster on the line.”

“ _Wha—sir, uh, one minute.”_

“You’re writing antivirus,” Other-Steve muttered at Toni, and demanded, “We’re on those teams,” while Steve barked, “ _Now,_ Agent.”

Fury narrowed his eyes at Other-Steve. “That’s a bit forward, son, when we only just met—”

“No better way to prove an alliance than a trial by fire.”

“I’ve kicked the Mandarin’s ass on three separate occasions,” said Toni cheerfully. “You could probably use the help with her.”

“Him,” said Fury, dry as the Sahara.

“ _Steve? Listen, I think we just got a signal from—”_

“Same difference.”

“Jane, I know. We have a team headed downside—”

“ _Wheels up in sixty, Cap. Get your ass up here.”_

“—we need a portal to the coordinates in that signal.” Steve took a tablet than an agent was trying to offer him—it was, somehow, a briefing summary on what had been in the signal. He tried to smile a thank-you, but the agent had already disappeared. “Bruce, ride’s on deck if you’re coming—”

“Of course I’m coming,” Bruce snapped. There was emerald around his irises.

Steve nodded. “Good man.”

“ _Forty-five...”_

“We’ve got our own way down,” said Other-Steve, as Steve and Bruce ran for the quinjets.

They made it with barely a second to spare: the hatch began closing behind them almost before they were properly on-board. Clint and Natasha had reached it ahead of them, and were checking their own gear; Clint had a second quiver, smaller than his main, and was doing something complicated-looking to attach the two together. “At that rate you better have brought coffee,” he called.

“Heads up for briefing,” said Steve, toggling the tablet to project a large-scaled hologram of a subterranean facility: something not built _on_ a mountain so much as mostly within it, with the position of various hostiles mapped, a snapshot of the moment Tony had sent it. The image shuddered as the jet lifted off beneath them and Steve had to shift his footing. “Jane’s going to send us right to the origin—we’ll be in this hall, here. Immediate hostiles are likely to include Borjigin and Fin Fang Foom. Hulk smashes Foom with Hawkeye providing support; Widow and I will take Borjigin. Primary objective is recovery of Stark.”

“ _If you don’t mind me stealing your thunder,”_ Toni’s voice came over the quinjet’s rear speaker, _“we have here the perfect opportunity to spring me as a surprise. From the way that signal cut off, your Tony Stark is down for the count. My Cap can assess and protect; I’ll join Local Cap and Widow in taking on the Mandarin. If he moves like I’m familiar with, I’ll go in for the knockout—otherwise, I’ll let you know and we’ll tag-team him.”_

“Agreed,” said Steve, dropping the tablet in a pocket-holder as the quinjet’s rapid descent slowed into a hover, and accepting a mini first aid kit from Natasha to stick in one of his belt pockets. Clint finished assembling his join quiver in time to hit the hatch release. “If any parties aren’t there, tertiary objective is capturing Hansen and any data they have on extremis. Widow, what do we have for egress?”

“SHIELD carrier _Canopus_ in the Taiwan Strait, they’re scrambling quinjets, twelve minutes out,” she reported as they piled out of the jet. “Exit is up and out—we can’t count on fighter support, we’re already on thin ice with China.”

Toni and Other-Steve were already on the ground, waiting for them—Security, already on high-alert from the hack, took a look at the pair of them and nearly pulled weapons. For a moment Steve thought he was going to have to get Fury or Hill on the line, but someone on the Helicarrier must have been a step ahead of them, because the next second they were standing down and waving them all through at speed.

“If extremis is a problem, then we’ll need Iron Man on that,” said Other-Steve, as they ran for the lower levels, past startled scientists.

“If it is then you tag in—me, you, and Widow on the Mandarin; Iron Man doing whatever she needs to do,” said Steve, pressing his hand to the glass scanner to get them down to the Gateroom. The blast doors began to open ponderously—he found himself practically jogging in place, waiting for them to inch open just enough to squeeze through. “Hawkeye, keep an eye on the field.”

“Always do,” said Clint, sounding insulted, as Steve gave them a last once-over. Eight inches open—Natasha squeezed through ahead of them. Bruce had his fists clenched; he was carefully looking at the ground, and Steve couldn’t see if his eyes had gone green or not. Twelve inches—good enough.

Beyond was more chaos, scientists running around—“Tell me you’ve got it calibrated,” Steve called as he caught sight of Jane standing over the primary control console.

“Bruce is a genius and so am I,” she called back. “Yes, it’s calibrated!”

“Actually, we haven’t tested it over more than a hundred miles, it’s not clear what the Earth’s rotation will do—”

“It’ll work!”

They assembled on the ramp.

“Closer together,” said Jane, and they all huddled in. Other-Steve’s shield pressed against Steve’s shoulder. Bruce, standing in front of them all with his eyes squeezed shut, was radiating heat like a furnace. The eyes of the laser at the far end began to glow, and scientists scattered away from the centre of the room and toward the relative safety of the far walls. Steve closed his eyes.

Light burst in front of his eyelids, and there was the feeling like surfacing from deep, deep water, gasping in that first precious breath of air—

“SMASH!” boomed the Hulk, and Steve opened his eyes and threw himself forward into a roll into clear space, before the pause could be taken advantage of.

Fires burned at the edges of his vision: the torches that Tony's databurst had shown. The high ceiling, the decayed tapestries on the walls, the wooden door, shut and barred—and, in the darkness, looming, the sinuous coils of Fin Fang Foom, his scaled body over a dozen feet thick and several hundred long. A maw wide enough to swallow a car gaped open, showing a forest of serrated teeth, and far to the back of the throat, a blue fire burning. Steve raised his shield and shouted, “Down!”

Tony. Where the hell was Tony? There was a computer desk, chair, and table, all sized for humans, but no actual other human beings.

Fire burst in a haphazard spray and the Hulk roared; Steve risked looking out from behind his shield to see that Hulk had jammed himself between Fin Fang Foom’s teeth, putting himself directly in the line of fire. The dragon screeched with pain as his own flames were turned back on him, and then Hulk ripped out one massive tooth.

“ _Mandarin’s skedaddled—nope, I have energy signatures. I’ve got a lock,”_ Toni announced. _“In pursuit.”_

“Not alone, you aren’t!” yelled Other-Steve, as the Iron Man armour blasted toward the door. Toni put out one hand and Other-Steve grabbed on just before they burst through the door, rendering it into so much kindling.

“Widow, scout,” Steve ordered, and he spotted Natasha sprinting after them as he took another desperate look around. “Stark’s not here.”

An arrow shot from a high angle—had Clint found a perch already?—got stuck in a scale and then exploded a second later, forming a small crater in Fin Fang Foom’s flesh. The dragon writhed and its body smashed heavily against one wall, instantly dousing all the torches along it. But this place was the heart of a mountain, and heavily built. The impact resonated through the stone and up into Steve’s bones, but the wall barely dented.

Nonetheless, they needed to finish this quickly. Fin Fang Foom had broken his way out of a mountainside before—if he got his wits about him there was no telling what he might be able to do. “Headshots, Hawkeye,” Steve ordered tersely, and sent his shield flying out, arcing toward one great eye.

Fin Fang Foom roared again, blue fire that flickered green around the edges, and the Hulk roared—in pain, this time. And then again, in even greater anger... before jumping right down the still-open throat. Out of what seemed mostly to be reflex, Fin Fang Foom swallowed.

“ _Did he just—”_ Clint sounded stunned.

“Yep,” said Steve, and launched himself up off the table. He hit Fin Fang Foom’s nose dead on and somersaulted, barely getting a grip on his shield before the dragon’s suddenly increased writhing threw him off and into a wall. He hit shield-first and bounced off, managing to land in a roll that bled off his momentum.

“ _Doc’s gonna love this,”_ said Clint, and was suddenly there, hauling Steve up and toward the exit. “Come on, give the guy some room—”

“ _What happened?”_ asked Other-Steve.

“Hulk read Jonah’s playbook too,” said Clint cheerfully, and that was when the top of Fin Fang Foom’s head exploded, the Hulk hurtling out from the wound like... well, a giant head-bursting monster.

Steve gagged—less from the sight, which was mercifully half-shrouded from view, but from the sudden stench of blood and alien brains. Human remains were terrible, but this smell was a step even beyond that. The Hulk, judging by his roaring, didn’t appreciate it either.

“Dragon’s down,” Steve grit out, as the massive corpse collapsed along the floor.

“ _Eyes on the Mandarin. He's got your Tony.”_

“Hulk, let’s go smash!” Steve called, running for the exit, Clint right on his heels.

“ _He’s mine,”_ said Toni, and through Other-Steve’s radio—it couldn’t be Toni’s; hers was crystal clear through her version of extremis—Steve heard the sound of an explosion.

“ _Stark’s got some kind of collar around his neck—Iron Man, I need a cutter for this—”_

“ _Hangar exit’s sealed_ ,” Natasha reported in, sounding slightly breathless. _“This place has a hangar, by the way. I could use some backup getting upstairs, there’s a lot of ninjas here.”_

“Great. Conservation of ninjitsu kicking in?” Clint panted, breathing hard as they rounded the steps. Hulk was thundering closely behind them, knocking down bits of the ceiling and walls as he went; he was too big for the narrow stairwells. Black-clad bodies lying motionless on the floor told the story of prior encounters between their team-mates and the occupants of the base—two slumped in the stairwell, and then five more scattered around the hall that they emerged into. One of those five was half lying through an open doorway. There was another trio of bodies beyond, down a larger hallway.

More interesting was the massive hole in the roof—about Iron Man sized, and recent enough that dust was still trickling down from it. Unlike the hall down below, this one was only partially buried. High, thin windows let in light from outside, but both they and the hole were at least two feet deep. Somebody had been in a hurry.

“Hawkeye, go assist Widow. Hulk—toss me, then follow Hawkeye,” Steve ordered, skidding to a stop. A moment later two enormous hands engulfed him, and he nearly retched at the smell of more alien brain-matter, which was _all over_ Hulk. Before he could, Hulk sent him flying upward at an angle high enough to clear the hole in the roof. Steve stiffened his body into a board to clear the sides, then spread flat to catch air resistance, belatedly realizing that he might have just asked Hulk to toss him out a hole and off a mountain. _Crap._

He hadn’t. But the slope that the complex was buried beneath was steep. Steve snapped his arms out and caught hold of a rock out-cropping before he could go tumbling out of control, then got his feet under him. High above, something exploded—Steve looked way up and caught sight of two tiny figures dancing around each other in the air.

“ _Stop showboating and force him down,”_ Other-Steve ordered, and Steve caught sight of his counterpart further up the slope. He scrabbled up toward it, relying on his boots' grip to avoid losing his footing on the snow and ice, and got up to where it flattened out. Other-Steve had his shield out and ready—and, there, further back, was a body on the ground that wasn’t wearing black.

Iron Man swooped around and detonated flares high above. The second figure, Borjigin, avoided them handily, until some sort of secondary burst activated and they remains of the flares swarmed him like a nest of angry hornets, ones that exploded in his face. Months ago, Borjigin had been able to handle a couple of Clint's exploding arrows, but fifty smaller explosions at once proved too much for him; he went into an out of control spin and tumbled mountain-ward. Other-Steve tossed his shield and took a running leap. The shield went flying away, but he actually managed to catch onto Borjigin, yanking him down. Borjigin, tangled up and struggling with his wind-controlled flight, kicked at him and pulled them both skyward; lightning flickered from his other hand, there was a squeal as Other-Steve’s comm shorted, and Steve could hear him yelling in pain; he threw his own shield. Toni fired down at them, but obviously on low-power—and then Steve’s shield caught Borjigin in the upper arm, clearly snapping it. But now both Borjigin and Other-Steve tumbled toward the ground with no sign of flight.

“ _No stealing my tricks, Steve!”_ said Toni, diving to catch them both and slowing them just before they hit the slope a hundred feet downhill. Borjigin wasn’t down—he launched a triple beam of fire, ice, and lightning, energy gouting into the sky... and then Toni grabbed his wrists. Steve couldn’t quite see what she did after that, but Borjigin screamed, screamed—and went blessedly quiet when Toni rammed her helmet into his head.

Steve ran for Tony. Other-Steve had put him in the recovery position, and the slightly smouldering remains of the collar he’d described were lying a few feet away, along with what looked like one of the laser cutters that Steve had seen SHIELD agents use before. “Tony?” Steve asked, although he didn’t expect a reply. Both breathing and pulse were obvious, but Steve checked them both anyway, the motions automatic. Tony was twitching, slightly—was that overload from getting the collar off, or from whatever had happened while it was on?

God _damn_ Borjigin. The last thing Tony needed, that anyone needed for Tony, was another God-damned collar on him.

Out of the corner of his eye, he saw Other-Steve getting to his feet—thank God. He certainly owed the man. Toni was doing something to secure Borjigin. Steve pulled out his mini first aid kit. This one, thankfully, had one of the ultra-collapsible thermal blankets, and he pulled Tony up so he could wrap him in it. It was more than a little chilly on this mountain-side, and the rock that Tony was lying on wasn’t any warmer than the snow.

“ _We got Hansen,”_ Clint reported.

Steve checked the time. Three minutes to pick-up—here was to hoping that the Chinese hadn’t noticed Iron Man’s aerial showdown with the Mandarin. “Rendezvous at the top of the mountain, we have Stark.”

“ _After we finish looting the labs.”_

“Two minutes,” Steve warned them.

“ _Hawkeye, take the left side—Hulk, smash those guys!”_ Natasha ordered. Hulk’s roaring echoed up from the hole in the mountain, sounding a lot happier than before. Presumably he was having more fun with ninjas than he had been with dragon brains.

He should hand Tony over to Toni and Other-Steve so that he could go back down, lend them a hand—Tony stirred in his arms. On the other hand, leaving Tony to be woken up by strangers was a bad idea. Steve rubbed a hand over Tony’s back as Tony curled inward on himself with a low groan of pain, his movements worryingly weak. Pulse was rapid, but his breathing was at least normal. Two minutes out... “Tony? Can you hear me?”

“Steve?” Tony mumbled. Steve twisted down so he could look him in the eyes, but Tony’s eyes were only half-open, un-focused. “You... huh. Rescue...”

“Ran over here as soon as we got your message,” Steve told him.

“Oh,” said Tony, and he seemed to relax, his head lolling sideways until Steve shifted so that Tony could lean on him. He was shivering properly now—probably a good thing, considering how cold it was out here and how cold he'd been when Steve had gotten to him. Steve pulled him closer anyway, shifting the blanket so that it was around both of them and he could lend Tony whatever body heat made it through his suit.

“Status?” he asked over the radio.

“ _We’re good,”_ Clint replied breezily. _“Egress still on schedule.”_

Down-slope, Iron Man had finished stripping Borjigin of his rings, and tied him up with a thin length of cable. She pulled her helmet off, shook her hair out, and caught Other-Steve up in a rather extended kiss as he was bending over to inspect her work. Steve blinked. Seeing that was... weird. And the level of enthusiasm they were putting into it seemed like the kind of thing that most people kept behind closed doors even in this millennium.

“...Is that us kissing?” Tony asked, vaguely confused.

“Alternate reality counterparts. They’re married. Very nice couple. Mostly. He’s a bit of a hard-ass.”

“Oh,” said Tony, still not sounding like he cared, nor like he was particularly awake, for that matter.

Steve averted his eyes as the kiss... extended some more, and glanced down at Tony, who had slumped further against him. Tony’s eyes were shut again. Damn—until Steve knew that whatever was wrong with Tony had nothing to do with getting lost in the internet, he’d prefer if Tony remained awake and talking. Coherent would be even better. “All those alternate worlds out there, alternate versions of ourselves,” said Steve, squeezing Tony’s shoulder gently. “Makes you wonder, huh?”

“No,” mumbled Tony. “I saw it already... all the ways it could have gone. Went. Just for a moment... before... before...” His eyes opened again; he started struggling to sit up properly. “Just before—Steve?”

“Yeah, right here.”

“Oh, god, you—are here.” Tony brought up a hand and pressed the heel of his palm against his forehead, blinking hard and slumping over sideways again. “You’re here! You got away! You— _agh_ , shit fuck, my fucking head, fuck...” His eyes were still hazy, unfocused despite all his efforts.

“Got away clear, and stop trying to access extremis if it’s hurting you,” Steve scolded him, as an unfamiliar voice came in over the comm saying, _“Avengers, this is Sierra Nine, ETA in fifty.”_

He clicked the radio in acknowledgement. “Status on the Chinese?”

“Foster?” Tony asked.

“ _No movement yet—no, wait. Sorry, Captain, spoke too soon. We’ve got activity on radar, estimated ninety seconds out.”_

He let his mic click off. “Foster’s fine, too. You’re the one we’ve all been worried about. Hawkeye, Widow, you’re out of time.”

“ _Guess what we found!”_

“Wait,” said Tony, still struggling to sit up. “Wait, I need—I _dropped_ —who the fuck _are_ you?” he demanded, apparently staring at thin air, but a hundred feet away Toni backpeddled and clutched at her head. Her yelp of surprise echoed up the slope. “Christ, this is—yes, okay, whatever, I dropped—”

“Team channel, guys,” Steve ordered over the same, as Iron Man boosted herself into the air, patted Other-Steve on the shoulder, and rocketed toward the hole in the mountain, disappearing from view.

“ _Technopathy, Local Cap, get with the times,”_ Toni announced.

“ _Ten seconds out—this is going to be close, Captain, we’re blocking overhead satellites but the Chinese are right behind us.”_

“Guys, _out_ ,” Steve ordered, standing and lifting Tony into his arms. Tony made a noise like a protest, but Steve ignored him. Thankfully, a second later Toni rose back out of the complex, lifting Clint and Natasha both by the back collar of their suits, which were reinforced for just such purpose. Her armour’s right elbow was crooked at an odd angle, like she had something under her arm. Clint had Hansen tossed over his opposite shoulder; judging by the limpness, she was unconscious.

Toni didn’t bother to let go before the cloaked SHIELD troop-carrier started landing practically on top of them, and then she dropped them all onto the ramp. Other-Steve had slung Borjigin over his shoulder, and he vaulted up to join them as Steve jogged over.

“Hulk?” Steve called. There was a roar, then the sound rock being smashed apart, and the Hulk leapt up through the now-much-enlarged hole. He was carrying a giant metal box, at least three by two by two yards, and when he jumped onto the carrier ramp, the metal—reinforced to take the Hulk’s usual weight—groaned dangerously.

“ _In, in,”_ said Iron Man, and then boosted herself out to collect Steve by the scruff of the neck and deposit him and Tony well inside, away from the overstressed ramp. She held out a hand and dropped apparently nothing at all onto Tony’s chest—except that Steve felt something roll down to bonk gently against his own suit. _“I am restraining myself from keeping this to study only because you look so miserable. Also, I expect you to share.”_

“I’ve been electrocuted, go away,” said Tony, indeed sounding miserable, but also thankfully more aware of what was going on. “I—Jesus, Steve, put me down—”

Steve headed for the medstation—the good folk of the carrier _Canopus_ had sent along a medical team, thank God—and deposited Tony on the cot, helping to strap him in as the troop carrier accelerated away; Natasha and Clint were doing the same, with prisoner restraints, with Hansen and Borjigin. “We miss the Chinese?” he asked his radio.

“ _We are free and clear,”_ came the smug reply.

“No, damnit,” said Tony, trying to sit up despite how he was shaking all over, and he did something and was suddenly holding an arc reactor, and fumbling with the shirts he was wearing.

Steve swore and helped him move clothes out of the way. The hole in Tony’s chest was an ugly thing, far too deep, and Steve closed his eyes with momentary relief when the arc reactor clicked home. Tony, relief suddenly relaxing his face, leaned back and let the medic stick an oxygen mask on him.

“ _Please let me out of the box,”_ said his voice in Steve’s ear.

Other-Steve answered first, raising his voice to be heard across the bay over the sound of the engines. “Try rephrasing that so it’s clear you know it’s not you in the box, first.”

“ _Wow, he is a hardass,”_ said Tony, and there was something just a bit closer about the quality of the sound that let Steve know that that had been said to him only. Then, on the team channel, he added, _“Please let my_ armour _out of the box, so I can check it’s all there and not left lying around for foreign governments to find.”_

“Compelling,” noted Toni. She’d taken off her helmet again at some point, and her hair was standing all askew, even worse than Tony’s got. Steve hadn't thought that was possible. “Hulk, mind standing back? Thanks, big guy.” She popped out one wrist-laser—hers were green—and sliced through the mid-section of the Hulk’s enormous metal crate.

Silvery extremis poured onto the floor and everybody, even Hulk, edged backward from it. For a moment it seemed like it wasn’t going to do anything after all, and Steve’s heart leapt absurdly in his throat as the medic leaned over Tony, asking, “Mr. Stark? Mr. Stark, can you open your eyes?”

Then the metal began to reform. Slowly, haltingly—kind of like how the zombies moved, and Steve gripped his shield tighter—and then more swiftly, colours flashing onto it, turning it from molten silver to familiar gold and red. It sure looked like all of the armour: a metal suit, and Steve would never have known there was nobody inside it if he hadn’t still been holding onto Tony’s hand. Tony squeezed his fingers, weakly.

“He’s awake,” Steve told the medic, who muttered, “I’ll fucking bet.”

“ _Subspace,”_ said Tony from the suit’s speakers. _“You know, I think I’ve figured out a better way to cancel the harmonics.”_ The panels that Steve had come to recognize as the things Tony used to access his subspace pocket slid out from the armour’s forearms. Steve let go of Tony to clap both his hands over his ears, but this time, when black light flickered around the armour’s hands long enough for it to pull an arc reactor out of nowhere, it made no more noise than a loud ‘pop’. _“Yeah, totally have.”_

“I’m halfway between jealous, and horrified at your energy uptake,” said Toni. She was staring at Tony's armour with a sort of glazed look over her eyes that made Steve think she was using her own version of extremis to get a much better look than any of them. “Are those your efficiency algorithms? Crap. They are crap. That is two-thousand-seven _crap_ and where do you think you’re going?”

The carrier skewed, slowing, and everyone who wasn’t strapped in grabbed for handholds. Hulk, halfway into the process of turning back into Bruce, went flying into Clint, who didn’t quite manage to catch him, and then into Other-Steve, who did. “Stark!”

The rear hatch was opening; emergency oxygen masks popped from ceiling hatches as the cabin depressurized. Over the roar of air, Steve could barely hear the clanking of Tony’s armour headed for the hatch. It jumped into flight and vanished before it was properly gone, invisibility cloaking it—more than invisibility; the sound of the jet boots had cut off, too. The hatch started to close again, dropping the noise level enough for them to be able to hear the near-panicked instructions of their pilots to prepare to bale out.

“Clint, see to the pilots,” Steve ordered. “What the hell, Tony?”

“ _I dropped the Space Gem,”_ Tony replied. His mouth moved, but the words were coming from the earpiece alone. _“Probably... I was distracted. I think think I dropped the Time Gem. I dunno where it fell.”_

Steve blinked, and looked over at Natasha, who made a gesture of frustration back at him. But she'd reported that Tony had gone into the Gap to retrieve the Time Gem, and now he still didn't have it, weeks later. Something must have happened. Had Loki ambushed him? 'AED,' he mouthed to her, an urgent question, and she shook her head, pointing up at the roof—no, at the jet around them. 'Silencer?' he asked, and got another grim headshake. If they'd had one, it had just left with Tony's armour.

“ _There,”_ said Tony, and far more suddenly than it had left, the armour was back, blinking into existence in the hold without need of doors. One fist was upraised, faint purple light leaking from between its fingers—and then the black light of subspace surrounded it and hid it away. The armour froze where it was as soon as the subspace panels had retracted again. _“...I’m going to pass out now.”_


	14. Weapons of Words: 3.3

TacSit: safe(89,00.00) 

Queues dumped info into Tony’s conscious awareness as he opened his eyes. Information on his surroundings: SHIELD HQ, New York, Sub-basement nine, his lab; Steve was doing paperwork at the desk that Tony had never used; somebody had dragged in a shit-ton of medical equipment and hooked it up to Tony—he turned all of it off before it could register him as awake. Tagged persons: Steve—three-point-three metres away; Bruce was Brucelike and debating with Foster one sub-basement down; Natasha and Clint were off-planet—according to the logs, they had portalled out with the alternate-reality doubles two-point-three hours prior; no Asgardians detected on Earth. Security updates on locations of interests: green lights across the board where installation was complete, and yellow lights within acceptable parameters for those areas undergoing upgrades.

Extremis staggered it so that his waking mind could swallow it down without difficulty. By the time he blinked, he was alert and oriented to the present situation.

“Hey,” Tony said, sitting up and wincing, not because he hurt—he actually felt great—but because the info-scroll had gotten to the repair reports, and, wow, getting electrocuted had really done a number on him.

On the other hand, the casualty report had come back with the damage his stunt had done to other people: 0 fatalities, thanks to the truly heroic efforts of various doctors and a couple of SHIELD pilots.

But there’d been close calls. He should have found another way.

_Story of my life._

“Tony!” Steve said, looking up. The beginnings of a smile immediately turned into a frown. “Did you just turn off all the monitors?”

“I’m fine,” Tony assured him, doing a scan of Steve in return. Discreetly. The records were showing that Steve had been cleared by medical, after all.

“You were electrocuted.”

“Yes, and now extremis fixed me and I’m good.” He felt, suddenly, like grinning at Steve—and did, although the cameras showed him that it made him look slightly unhinged. “You came and rescued me.”

“Of course we came!” said Steve indignantly, but his eyes had softened, and he didn’t immediately say something more about electrocution—

“Yes, but you came _right away_. Bonus points for you. And for the successful rescue. And for making me look bad, Jesus, I was supposed to be rescuing _you._ ”

Steve grinned back at him, somehow managing to look both relieved and concerned at the same time. “It was a team effort.”

“Yeah, I know,” said Tony, and it was probably really damn sappy but, shit, it was also true. He could see it all over the video logs that extremis had just finished processing for him. He could also see it because he actually had an email from Bruce, the timestamp putting it just after the email from toni.stark@starkenterprises.com.

“How’d the Chinese take it?” he asked, pulling open both emails at once. Toni’s was a mess—their two versions of extremis weren’t entirely compatible, which fit with the logs stating that her version was wholly designed by Hansen and herself, and hadn’t had anything to do with aliens. That was humbling; he had to give them points for that.

Hansen might get the chance, someday, to prove that she could do the same. Tony paused to pull the most recent updates on her, and reconsidered his estimate of how long it would take her upwards. SHIELD’s preliminary position was that she’d blown it, releasing extremis before it was ready, and then failing to fix it in the months since. She was considered too much of a risk, too uncontrollable.

What it really came down to was that she didn’t have anyone like Steve to speak for her. Or anyone who held enough over her head to guarantee her compliance. _Aaand_ that was one way to kill the endorphin high he'd gotten from knowing that Steve had come through for him.

Loki had taken Steve, and shortly thereafter somebody had used the—had used the mantra. It didn't take a genius to put the two together, not when Loki could look into your eyes and pick thoughts out of your brains, leaving you wondering what he'd seen. It wouldn't have been Steve's fault. It wouldn't have been. Steve had to know that—Tony should tell him that. Steve, being a too-decent human being who valued his word, was probably blaming himself for breaking it even by proxy, but even Tony knew it wasn't his fault.

Tony licked his lips. He should say that. He could _think_ about the damn mantra now, Gaia's water had done that much, he should be able to say it.

Steve wasn't saying anything either, and the silence stretched out for one second, two.

Does _he know what Loki picked out of his head?_

When Loki had done it to _Tony_ , he hadn't been able to tell what Loki had grabbed, but he'd known Loki had done something. He'd _warned_ Steve about it. Surely Steve must realize what Loki had gone for.

Steve's smile faded, and he studied Tony just as intently as Tony was studying him back, but there was no trace of guilt in his eyes. Had Tony gotten it wrong? No—the timing was too suspect, the whole thing was too damn suspect. Who else would Loki have gotten it from? The Time Gem's perspective on the Makluan time loop only vaguely made sense, but it had only taken one run through to get the idea that Tripitaka was deader than dead, and good fucking riddance. In fact, most of Maklu was pretty damn gone, which likely ruled out Kuan-yin, although Tony didn't doubt that she could given Loki a run for his money in mind-screws. And if Loki had gotten it from _him_ , picked it out of Tony's own head back in that cell in the Raft, then why the hell had he waited so long to use it?

_He hasn't come after the Space Gem. Yet._

He had to break his gaze away from Steve's to be able to keep thinking.

It was possible Loki just didn't give a damn about the Space Gem, and only needed the Time Gem for his plan, whatever that was. Or maybe Loki was just letting him hang onto it until the time was right to take it from him. Trying to out-think Loki made his brain itch. Trying to think of resisting him, now that he _had_ to have the mantra, just made him feel sick. If Loki _was_ after the Time Gem, then leaving it in the Gap was likely the safest path.

But there were other monsters in the Gap, and he didn't know if Thanos would be as averse to treading there as Loki was. And now that Tony had put the Time Gem back together, anyone who wandered in might find it.

_Should have found another way. Idiot._

“—Tony?” said Steve, and Tony blinked back into his head to find Steve waving a hand in his face.

“Be right back,” he said in a rush, and activated the subspace inducers in the sleeves of his jacket. Black light flared and popped, and the Gem dropped into his grasp. Then, without bothering to pull on the armour—there was nothing there that could hurt him—he used the Space Gem to flip himself into the Gap.

He existed there as a bit of reality in nothingness. Looking for other bits of reality was just as easy as it had been before—but the Time Gem wasn’t there, either whole or in pieces. _Shit. Where did it go?_ He hadn't had it when he'd fallen back to Earth. Had somebody come and taken it? Or had it fallen somewhere else, on one of the myriad worlds he'd fled through while trying to outrun the mantra?

If there had been any reality to sigh in, he would have. There wasn't. Tony buried his face in his hands, and flipped himself back to Earth before Steve could start to worry, reappearing back on the cot, this time on top of the covers.

Too late. It had been maybe five seconds, but the furrow between Steve’s brows was deep enough for five hours. “What was that?”

Tony doublechecked the settings on the Silencer. “I, uh. I dropped the Time Gem, in the Gap, accidentally, before. The way it came together, it, um, was a bit hard to hold onto it.”

“You told us before—wait, you got it back?” Steve sounded startled, but there was no sign that he didn't believe what Tony was saying.

“No. It’s not there. If it fell out someplace, it could be anywhere, maybe anywhen. Finding it again’ll be a needle in a cosmic haystack, but hey, Loki’ll have the same problem.” Tony shrugged and made himself look up to meet Steve’s eyes. There was nothing there that said that Steve knew what Loki had done, or why it would have been hard to hold onto it—no, Steve didn't know anything about it. Of course he didn't. He would have apologized. He would have at least _mentioned_ it by now.

Loki must have had the mantra all along, and just been fucking with Tony all this time. _Fucking bad timing in yanking the damn chain, then._ Suspiciously bad. But— _fuck._

“You should probably take this,” Tony made himself say, holding out the Space Gem. Extremis let him actively prevent muscle tremors and ensured that his hand was rock-steady.

This felt wrong. The timing felt _wrong_.

_You're being paranoid. Just_ ask _him_ _._

“That's... a point of contention.”

“Oh?”

Steve grimaced. “Where would we keep it? Loki... we didn't have one of Foster's Silencers in the jet. If he was listening... odds are he knows we have it.”

“Shit.” _Shit!_

“Yeah. Toni said the security on your subspace pocket was better than anything she'd seen before—she couldn't get into it, at least. And you're a mobile target. Loki can walk through walls no matter how deep we bury 'em, we put it in a stationary subspace vault and the vault door becomes his target. _And_ ”—Steve held up a finger—“the space aliens gave it to _you_.”

“And,” said Tony pointedly, “Loki knows about—” He gestured at his head, the words cutting off at the last moment. The rest of the sentence wouldn't form. He couldn't make himself add: _He's used it._

“Fury agreed it's still safest with you.”

Because Fury thought Steve could keep Tony under control. Fury didn't know that that was only partly true. The override that Tony had given Steve wouldn't stand up to the control the mantra offered, not in the long term, unless— _No, he wouldn't. Damn it, I have to stop suspecting him._

 _He wouldn't. He_ didn't _._ And Loki might be able to root around in people's heads, but he'd never shown any sign of being able to rearrange them. He wouldn't need such overly-convoluted plots if he could. This was baseless paranoia, it was just _fucking bad timing._

But the words wouldn't come. He couldn't say it. Instead what came out was, “I'm surprised he's trusting Natasha's opinion.”

“She told us there were alien drugs. And yes, I was worried. Still am. The last person I was around who could read minds... I made sure not to meet his eyes.”

There it was: Steve's word. It was coincidence, then. It was Loki fucking with _Tony's_ head: he knew and always had known. Tony slumped.

Then he realized that Steve was waiting for him to respond to that, and scrambled for something else to say. “Gaea was different.” Christ, that was an understatement. “It was... there was nothing I could have given her.” Oshtur and Chthon hadn’t even cared about the Space Gem, it was useless to them.

It might be useless to Loki. Loki could retrieve it whenever he wanted.

Loki was an arrogant son-of-a-gun, and Tony felt a sudden deep need to make Loki pay for the mistake of leaving the Space Gem in his hands. _So I've got it for now. What can I do with that?_

“You’re still going to have to be cleared by the shrinks. And you’re still going to therapy.”

 _Saw that coming._ “To be fair, alien gods really do have a leg up on the pharmaceutical industry.” _And yet even they can't fix the fuck-up that is my brain_ _._

“I still can’t believe either of you _accepted_ it.”

“You’d take aspirin from your mom, right?” Tony asked, and then winced. It hadn’t sounded creepy in his head, but aloud was a whole other story. “I didn’t mean it like that.”

“I really think you did,” said Steve, watching him closely. “I guess, except for Natasha, I can understand it best. And you’ve got extremis, so I think Medical’s half washed its hands of you by now. But... God, Tony,” he said, and then stood up and crossed the gap between them in a few strides, so that he could fold Tony into a hug.

Tony squawked—he couldn’t help it, he hadn't been _expecting_ it—and then, sort of, hugged back. And then, because Steve deserved to hear it, “I’m glad you got away from Loki.”

 _I really hope you got away from Loki._ But that a baseless, ridiculous accusation that he couldn't even make himself say aloud. _Stop being so fucking paranoid._

Steve laughed, low and slightly stressed. Tony could feel the tension in Steve’s frame, all wound up with nowhere to go _._ “Yeah, well, read the report,” Steve said, stepping back and holding Tony at arm’s length—literally, his hands were still on Tony’s shoulders.“He’s apparently got ideas for the Infinity Gems—they're a set of six total. Loki thought we could help him get the Power Gem, but it was gone when we got there. Our new allies have some experience with the gems, by the way, or at least their reflections. I’m still not sure I understand the difference.”

Was that what was in the email from Toni? Tony brought it back up in his mind's eyes, but when he sorted out the errors caused by different operating systems, he discovered it was a gaggle of energy efficiency calculations instead. There was something about the layout that made it feel like a taunting note. At the bottom, in lieu of a signature, were the words _Your move_ and a brief segment of emotional coding that, when Tony unscrambled it, proved to be a feeling of good-natured challenge-slash-ribbing.

Her math was so blessedly clear and free of uncertainties that he could have cried over the beauty of it. “You know, I think I like her.”

“Natasha?”

“What? No—I mean, yes, I like her, but I meant Toni.” He started drafting a reply in his head—nothing alien, that would be cheating; he went in for the first-generation cloaking instead, because even if it wasn’t as efficient it was _his_ , and, anyway, he had the feeling that if he’d had the time to take it further, instead of switching to a more Makluan approach, it could have actually been a more elegant solution.

“Fury will be thrilled to hear it.”

“I'm sure he thinks the more of me the merrier,” Tony said, and hesitated, re-reading the much shorter email that Bruce had sent. It wasn't anything personal, just two sentences: _Prize is up above two million now. Take a look._

There followed a series of links, and only some were to math forums and wikis. The leading ones were news articles regarding a massive IT security clusterfuck that had occurred two weeks ago:

_...Hossmann is the first to proclaim that her work is not a solution to P vs. NP. “It takes us closer,” she says. “It shows that there are classes of primes and it increases the likelihood that P vs. NP is solvable. But it’s not a proof; it doesn’t show the general picture clearly enough.”_

_From a mathematical perspective, the Hossmann Algorithm may not be worth the million dollar prize, but to cyber-security its discovery is worth at least thirty-two trillion USD. That’s the amount VENUS Cybersecurity estimates would have been lost to cyber-theft before stop-gap measures could be implemented, had Hoffmann not forewarned IT experts in the field in advance of publishing her paper last Tuesday. “Just as thieves could use Hossmann’s Algorithm to detect ‘vulnerable’ primes and exploit them, we can use it to detect and avoid using those primes in our security,” said Arturo Marcelo, head of Security Services at VENUS. “We have had teams working around the clock and have closed this exploit.”_

_But it may soon be re-opened. Hossmann developed her estimation algorithm based on work she’d done in trying to solve the ‘Euclid Paradox’, which made shockwaves in the mathematical world when it first appeared earlier this year. Developed by a still-anonymous author, the problem was first presented on the University of California math forums only six weeks ago. On its face, the Euclid Paradox doesn’t look like a problem. It was presented in the form of two opposing theorems, each apparently logically continuous, that resulted in two conflicting statements. Initial reaction to the theorems—either of which might be groundbreaking work in the field of elementary mathematics—was that at least one had to contain an error. But no error has yet been found, despite the steadily increasing monetary prize for its discovery. (At time of publication of this article, the joint awards offered for the solution total to $2.2 million.)_

_Hoffmann, like many who are working on the Euclid Paradox, tried to find where the error lay by extending the results. Instead, she identified a new classification for prime numbers based on the dual-contradictory ‘proofs’ of the Euclid Paradox theorems. “From a mathematical perspective it’s not sound,” she says. “It’s based on something that defies formal logic. But practically speaking, it has real, applicable results, and if this one thing can, then I think it’s very likely that other extensions of the Euclid Paradox will, too.”_

On the forums Bruce had linked, those extensions were already being posted: ones with less _immediate_ implications, but IT security wasn’t the only part of the mathematical world undergoing a war between the purists and the engineers. Surfing for recent academic furors wasn’t part of extremis’ wake-up functions, but he was going to have to consider making it one—he clicked through, and through, absorbing the discussion of a few weeks in a heartbeat. There had been two serious contenders for a go at resolving the paradox, but competitors had shredded both within a few hours of posting. SHIELD had offered both jobs.

“The math still doesn't work.”

“What?” Steve said, now sounding very concerned, and it occurred to Tony that to Steve, this was a lot of conversational jumps in a very short period of time.

_Unless he's—_

But the thought of Loki wearing Steve like a skinsuit was horrifying and paranoid enough that Tony actually did manage to set it aside, because if that was the case then there was no point in doing anything except playing along. And hadn't that been what he'd been doing from the beginning, since Steve had pulled him out of the Raft?

“Sorry. I'm checking emails with my brain. Toni and Bruce sent me things—Bruce's been working on the math problem, the incompatible one. Hell, everybody's been working on it.”

“Yeah, Bruce said it actually stopped the music war in Gateroom Two—now they all argue about your math,” said Steve, and there was that smile, back on his face again. It made part of Tony's brain relax in relief, still thrilled with the knowledge that they had, in fact, managed to get him out of Borjigin's clutches. They'd come for him.

“I saw it. In the Gap, when I was using the Space Gem, and the Time Gem was breaking. Or I _thought_ I saw it. Brains aren't really made to see it, it's kind of fucked up.” And immediately after his brain had been fucked over. Maybe the entire thing had been a hallucination. Maybe not.

It wasn't like SHIELD's monitoring equipment could tell, so he took it for an excuse to start stripping leads from his skin. And if that gave him a reason to not be looking at Steve, then, well.

“Can't help you there, it makes no sense to me.”

“I... I think I should speak with Bruce. And Foster.” It felt almost shameful to admit it.

_When did your head get stuck so far up your ass that consulting with somebody else was shameful?_

Or so paranoid that it was terrifying...

Steve's eyebrows had climbed upward, but he looked pleased. “You need to debrief first.”

“Wrote a report,” Tony replied, which was jumping a bit ahead of himself; he was _writing_ a report, in his head. He set up a location to upload it to on the SHIELD servers and then padded the location so nobody could see it was empty, just locked. He’d have the report finished in a minute, anyway.

“A report’s not a debrief,” said Steve, but he sounded amused and happy enough to ignore it. “Let’s go see what they have to say.”

 

* * *

 

He was half-immersed in a pool of extremis when his visitor decided to stop by. Tony sat up, combat systems primed before he realized who it was—he hadn’t seen it from this end before. Nobody else could use the portable bridge, and whenever he'd used it he'd had illusions up, scrambling camera surveillance.

His older self dropped into existence surrounded by black flickers of the void and the kind of total silence that only came from using a Foster Silencer. He hadn’t even bothered with any armour, which was pretty stupid considering that Tony had nearly fried him before he’d realized what he was.

“You realize that the Time Gem breaks the laws of causality, right?” Tony asked him, although he was pretty sure he was going to be made to look like an idiot in a moment because of it. “And even if it didn’t, I could still accidentally kill you and it wouldn’t be a paradox.” Then he blinked, as some part of him that didn't have anything to do with extremis' sensor suites determined that future-him hadn't used the bridge just for funsies. “You don't have it with you. Either of them.”

“Nope. Sent ‘em on and portalled over here the manual way. You’ll need to send me to my next stop.”

“Why?”

He received a smile that was as mocking as any he'd ever given. “Better to avoid temptation. You know.”

“I don’t have to do this the way you’ve done it.”

“Don’t you?” Future-him shoved his hands in his pockets and leaned back on his heels, casting a derisive glance around the lab. There wasn't much to look at, considering he’d repurposed it out of a squat, one-story office building in Maine. No need for impressive subbasement layouts here: these were hardly high-energy experiments, and just buying an existing office meant he didn't have to install his own water main.

The body in the corner was probably the most interesting thing present. Future-him sauntered over and twitched back the sheet covering it. Beneath, his clone was lying on a block of extremis that contained all the original armour protocols, breathing slowly in and out, eyes closed. At present that was about all the body could do: autonomic functions were working perfectly fine, but the personality and memory matrices were still in the black box. Tony didn’t want to risk loading them until the last possible moment.

“Come on, like I don’t know what you’re thinking,” said future-him. “What are you going to do? Let this slab of meat rot? Toss the Gems in a volcano and never look back? We’re so close, don’t fuck it up now.”

Tony swallowed. He wanted to argue—wanted to bite back, words as vicious as he could make them, tear into his own soft spots. He rubbed at his face instead and stepped fully from the pool of extremis, separating it out from the armour’s makeup and shooing it away. “Why are you here, then? Part of the plan is to go gloat with myself?”

“No, I’m here to tell you to stop sitting around on your ass.”

“So, not here to be helpful.”

“Oh, no, I am. You’re stalling.” Future-him bared teeth. “You can lie to yourself about it, but you can’t really lie to _yourself_.”

“Stalling? I have the Time Gem. Considering what’s at stake if I screw this up, re-checking my work is a pretty damn valuable use of time—”

“You’re evading. It’s perfect, it’s been perfect the last twenty checks, you don’t need—”

“Oh, stop it, I’m blushing—”

“—to re-check it, you’re just wasting time—”

“Yeah, _Time Gem,_ time’s not a problem—”

“—you don’t have an infinite amount!” his future-self shouted, and Tony fell silent. “The Time Gem doesn’t matter when it's _you_ that's the problem. Drag your feet for another couple months and you’ll convince yourself to avoid it entirely, to _try something else._ Look at us! You’re going to throw it all away and get everyone killed because you’re tired”—and his sneer was Obie’s, was his Dad’s, not grandiose or frigid with ice and all the more cutting because of that—“because you don’t want to be the bad guy, because you don’t want to make the hard decisions. Well, too bad. This is what we are.”

They were standing nose-to-nose now. Perfect mirrors, firewalls up, code guarded. A decade and a half he’d been at this, and somewhere along the line it had turned from being about figuring out how to avoid Loki’s trap into figuring out how to fix everything, and he’d broken every promise he’d made to Steve—but once he’d realized he _could_ fix it, could he have chosen any differently? Fifteen years of working on this, alone and with Dyson, and he’d had more doubts in the past week than he’d had in the last ten years. Christ, he was such an asshole, and yeah _,_ he was fucking tired.

This was the first conversation he'd had with another person since he'd left Dyson behind.

Tony turned away first, and his future-self said, more restrained now, “Come on, I’ll give you a hand. Make the final transfer and you can ship this guy off.” He waved a hand at the clone. “And then... talk to Pepper. We’re nearly done.”

“Is that when you’ve come from?” Tony asked, not looking up and not bothering to hide the bitterness in his tone. What would be the point? “Convincing her to lie down on the wire?”

“A reputation’s just a reputation,” and he sounded just as exhausted as Tony felt. _No shit._

“She doesn’t deserve it. Any of it.”

“Of course not, but she’ll live. Cut your losses. Cut _her_ losses, come on. Work with me here.”

“Yeah,” said Tony. “Yeah, alright. Get me the—you know how this goes.”

Transferring the matrices was easy, with the help of somebody who knew his own brain inside-out. They worked in silence, completed the transfer checks and then checked each other’s own check-work. Tony pulled the Gems from his pocket and looked at his clone, still unconscious. He hesitated.

Future-him tilted his head. “Timer’s set. He’ll wake up in five, four, three—”

“Fuck you,” said Tony tiredly, and he shoved his clone and all the relevant nanites through time and space. For a moment longer he kept his awareness there, double-checking that everything was as it should be. It was, of course.

And then his clone was booting up and he had no excuse to linger.

“Where are you going?”

Future-him offered a crooked smile. “Last stop.”

“Oh.”

“Yeah.”

“Well.” What did he say to that? “Don’t fuck it up.”

“Same to you.” Then he was gone, too, as Tony sent him on his way with no more than a thought.

Tony stayed a minute longer, packing all the lab gear into subspace and then just standing there, thinking. The Gems felt almost weightless in his palm—they always did, even when he was actively using them to bend Time and Space to his will. _Was_ it to his will? With the Time Gem he could see how Reality was wrinkled out so that causality could, in certain cases, be ignored. It was all too possible that he was fooling himself, that he wasn’t the force behind any of his actions, that it was someone or some _thing_ else—

_So, what? Gonna test it? Could toss ‘em away. Pick a volcano, drop ‘em down the Marianna Trench, think ‘em into the centre of the sun..._

Tony shook his head violently. His future self was right: delay any more and he wouldn’t do this at all, he’d talk himself out of it, and wouldn’t that fuck up everything. In the end, what did it matter if it was his choice or not? All that mattered was the results.

He closed his eyes and willed himself into the past.

 

* * *

 

Tony had kinda forgotten how much _fun_ it was to discuss physics with other people. To toss around ideas, scribble math on the board, root out the rules of the universe. In deference to Jane, who was still eyeing him warily, he _did_ use the board rather than putting equations up holographically with his brain. When he and Steve had first arrived in the lab, newly released from debriefing, she’d half-frozen.

“Can I talk to you for a sec?” he asked Jane quietly, at one point when Bruce was the one scribbling over the board. Not quietly enough for Bruce not to hear, but quietly enough that Bruce kept scribbling, playing the escort looking away... giving them the illusion of privacy.

“I... what?”

“I’m—sorry.” Christ, he was terrible at this. “I—the research, and it... occurs to me I haven’t been—”

“No—you know, it’s fine.” She shifted uncomfortably.

Tony studied her without looking at her, even if that was sort of a low trick. He wasn’t sure if he should say the next thing, but she deserved his consideration. “I’m sorry about Ms. Lewis, too.”

She shook her head and sniffed, her face doing that weirdly rigid-not-rigid thing some people’s faces did when they were trying to compose themselves. Tony folded his arms across his chest and looked down, turning inward to try and give her some privacy. Among the follow-up reports from Loki’s abduction of her and Steve had been medical records. Tony hadn’t broken the privacy seals on those, except to learn that the first casualty, the barista, had woken up an hour later confused but in perfect health. Jane’s assistant, on the other hand, had been moved to a regular hospital’s ICU.

“It—never mind.”

 _Don’t push it._ Tony swallowed a sigh and looked up as Bruce stepped back from his whiteboard—and blinked.

“Did you just disprove Pauli’s Exclusion Principle?”

“I think so, yes,” Bruce agreed. His eyes had gotten rather round behind his glasses.

Jane sighed and buried her face in her hands. “The universe is falling apart,” she moaned. It only sounded a bit forced.

“Uh-huh,” said Tony. The sky hadn’t caught fire yet, they still had time to pretend it wouldn't. Just a little bit longer. The equations tickled something in the back of his head. He let it simmer, and grabbed up another marker to start adding to Bruce’s work, pulling it in a few more practical directions. “How do we use that?”

“You are such a fucking engineer,” Jane muttered.

Eventually, Steve came back to collect them, this time accompanied by Natasha, Clint, and an invitation-slash-command to take a break and grab some dinner. Jane glanced between the five of them, and started to make an excuse to leave—“You had a time-and-space breaking adventure, you can stay,” Natasha told her.

“I’ve never had a time and space breaking adventure,” Bruce said mildly.

Clint, leaning in the doorway, snorted. “You break time and space every time you Hulk out, Doc.”

“No, that’s a subspace-inducing mass-shift effect,” Bruce corrected, putting his glasses away.

“It might not be,” said Jane suddenly, pausing in the act of shutting down some of the monitors. “Anymore, I mean. I mean, considering that formal logic is breaking down—”

“Break,” said Steve firmly, cutting off the thought. “Science after eating.”

Tony wound up holding up a wall as the others filed out, and after a brief exchange of glances with Steve, Natasha lingered, too. He raised his eyebrows at the pair of them— _Do you think I missed that?_

“That wasn’t subtle,” Tony informed her, falling into step with her far enough behind the rest that none of them, aside from Steve, would be able to hear what they were saying. And for Steve—Tony was pretty sure he could modify his duplicate of Jane's Silencer to prevent any sound from leaving. But, hell. He was already keeping one secret from Steve, he needed to stop before it became a dangerous habit.

“Wasn’t trying to be,” Natasha returned.

“Sorry.” He wished he could close his eyes, but he could feel all the security feeds, watching him. It was a stupid impulse anyway. Closing his eyes had never made anything go away. “I—sorry.”

“You did okay.” Her smile was small, but forgiving. “You think I don’t get it?”

“It wasn’t something somebody else put in my head. It was all... me.”

“So?”

“I just thought... you should know.” He glanced up at Steve ahead—no, better that Steve heard this. “Gaea, she... Christ, it was—“

“I was there; I know. You’re doing... better,” Natasha added, and... _well, fuck_. It wasn’t like he could deny that one.

He lengthened his strides so that they could catch up to the others by the time they reached the lower commissary. Not his ideal place for dinner, except that the cameras showed that it had been cleared out an hour earlier, save for a load of pizzas and beer that Steve had dropped off. _Steve, the secret party-planner._ It was a scene only slightly spoiled by the addition of Hill, sitting with slices of pizza already claimed and paperwork—actual paper—surrounding her.

“Give me ten minutes,” she said as they entered. “Romanoff, Barton, I need your run-down about Earth-3490.10.”

“Allies,” said Natasha instantly.

Clint nodded, grabbing a beer. “Yeah, they’re not faking it.”

“Their technology is several years ahead of ours. We’re closing the gap fast, but while they’re cautious of us, too, they have a lot of advances they wouldn’t mind sharing.”

Tony felt his eyes slide away. Should he—what a goddamned question to be asking now. “Toni sent me some algorithms, gratis.”

There was a pause as Hill scribbled things—paper reports, Jesus. _Maybe I should have kept my mouth shut._ Or maybe it wasn’t actually a precaution against _him_. Toni had her own version of extremis, after all.

“They gave us a whole stack of files on the Mandarin’s rings to take back,” said Clint, breaking the awkward silence. “Handed it off to the techies in lab four.” Where the rings were being held—to be studied at something of a distance. Borjigin himself was sedated in holding, until they had verification that they could block him from controlling them remotely—something else Toni had warned them about. “I wouldn’t say gratis, though, Tony. They want that thing you used to shut off Borjigin’s tech.”

_That’s not surprising._

“It shut off Natasha Stark’s extremis, too,” said Steve. He’d loaded up two plates with pizza, but to Tony’s surprise, he came and handed one over instead of having them both for himself. _...That shouldn’t have been surprising, either._ “I’ve been debriefed about it, already, and the counter, but that defence needs to go global, Tony.”

Tony nodded, looking down at the plate in his hands, and let Steve prod him into taking a seat. “The virus... it spreads with the signal. It’s stickier than the counter. Goes places. I’ll have the global defence up by tomorrow, something for handing out to allies... in a report. Later. I—sorry.”

At this rate, he might actually get decent at apologies. He wondered if they’d ever stop feeling like failures.

But... lesser failures, if he could only get past them.

“Captain Rogers already fell on that grenade for you, Stark, and in fact we’d prefer if you kept your mouth shut about it,” said Hill. Hmm, maybe not improving on apologies, then. “Moving on. The Mandarin’s rings are showing marked differences to the readings on them that 3490’s given us.”

“You go to their world, you’ll see some pretty marked differences in the entire thing.”

“The physics might actually be different,” said Jane, twitching a bit as she got the full attention of this bunch—except for Tony, who kept staring down at his pizza, thinking. The back of his brain watched through the cameras instead. “Uh—I mean, it’s one of the things we’ve worked out.” She gestured between herself and Bruce, and then included Tony almost as an afterthought.

“So it may or may not have any use,” Hill noted, pen scratching.

“Or it could let us be more flexible in our solutions,” said Bruce.

“We’ll need to exchange more scientists,” said Steve firmly. “That’s always been the plan. Deputy Director, do we have approval to go ahead?”

“If we don’t, we risk losing both initiative and control,” said Natasha. “Toni Stark with extremis was wandering around our world most of today. 3490 is a player now and they _will_ act to respond to Thanos.” She wasn’t saying it to Hill, Tony realized. She was saying it to Steve—and she wasn’t saying it to try to convince anyone. It was just a statement of fact...

_Does she think—!?_

_No,_ he realized when Steve and Hill both nodded, playing along in the same fashion. Tony made himself look down, resisting the urge to directly tamper with his heart-rate to bring it back to baseline. This wasn't anything more than the usual power-plays of SHIELD. He should have wondered earlier why Fury had let an unknown factor with extremis loose with so little debriefing. _Hell of a gamble._

Well, Fury made those.

“Fury’s meeting with the Council now,” said Hill. “I’m sure he’ll have that argument in mind.” She pointed her pen at Clint and Natasha. “Synopsis, now. And no input from either of you,” she added to Steve and Jane.

Tony picked at his pizza—real New York pizza; it deserved better than the attention he was giving it. Most of his brain retreated down to lab four. The scientists’ readings on the Mandarin’s rings were were giving a whole ocean of data that didn’t make a drop of sense... by the rules of physics as they knew them, anyway. But either Thanos was twisting those, now, or something else was. It wasn’t just formal logic that was changing; things at the fundamental levels of physics were now—wrong. Illogical. Contradictory. It hadn’t affected anything on a macro level yet, but...

He took a bite of pizza so that he had an excuse to swallow the lump in his throat. If everything was changing—he started setting up loops, simulations, branching off part of himself to hook into the extremis banks in his own lab and run them from there, constant updates, but he saved a copy in his own hardware in case he needed to go off-world again, too. If things changed too much, everything they had could fall apart—

_Hang on before you convince yourself the sky is falling. It’s not like the numbers changed._

Things were wrong, paradoxical—but it wasn’t like they were finding contradictions between now and what _had_ been. If reality was breaking down, it was doing so—already had been doing so—

_The time-differential shouldn’t matter._

He set the simulations to run anyway. No point in being caught off-guard.

One of his watchdog programs pinged his attention, drawing him aside, and he abandoned what he was doing with lab four’s computers, spinning his brain out until the underground commissary seemed very far away. His mind was in the neon lights, the flash-bulb glare... the cameras rolling on _Tonight with Montegue Hale_ as the titular show-host said, _“—with the most insight on the planet into the infamous creator of the Nanovirus—please welcome Ms. Virginia ‘Pepper’ Potts!”_

She walked onstage to applause that was half-hearted, more shocked than anything else. God, she was beautiful. All confidence and command, not a hint of nervousness, even though she was flushed beneath the heat of the lights and her makeup and her immaculate white business suit. She didn’t give a damn what the live audience was doing, and every person in that room could feel it... every person watching live in on TVs across North America.

“ _Thank you, it’s good to be here,”_ she said, shaking Hale’s hand and then—because Hale was a pig—accepting the hug that he pulled her into, kissing his cheek with complete decorum. _“It’s good to be back in_ America _, and not be running from my own government anymore.”_

Hale leaned in eagerly as they found their seats. _“Wow, okay, we can start there. You’re saying that all those crazy rumours, about you being ‘disappeared’—”_

“ _They were very nearly true,”_ she agreed smoothly. _“I was detained without charges, and in the hours before my escape I was restricted from access to lawyers. All my assets were illegally seized and frozen—everything I have now is, you could say, ‘borrowed’—”_

The alert was pinging him steadily now: announcements on Twitter, mostly. His watchdog didn’t track all mentions of her—she had whole hateboards dedicated to her, just like he did—but rather sightings and feasible threats. After a moment of frozen shock, he disabled alerts relating to the former. He damn well knew where she was _now_.

“ _Okay, okay, but hang on, back up,”_ said Hale. _“Start us at the beginning, Pepper. This begins with the nanoplague. What everyone really wants to know—I mean, you probably told the government the answer to this question, but good luck getting them to release anything to the public—did you know? And was Stark’s death really a suicide?”_

Somebody passed him a pizza-box, headed toward Steve. Tony took it without thinking and handed it over.

“ _Tony blew his head off with one of his own weapons,”_ said Pepper. She blinked twice, rapidly, and that was it. _“I can attest... that was definitely suicide. What surrounded it—leading up to it, and the nanoplague—”_

“ _So did you know something about the nanoplague leading up to it? They were linked,”_ said Hale, and he was leaning forward eagerly now.

A nudge to his ribs: somebody's elbow. “Hey, Tony. Break-time.”

“ _The nanoplague—_ god _, you know, I just, I hate that word—”_ And for a moment she looked righteously angry, and everything in Tony’s brain was throwing up warning signs. But she wasn’t wearing an earpiece, and he couldn’t say anything to her. _“Look, whether or not I knew, it wasn’t a_ plague _. That was a bunch of disgruntled ex-con employees, and frankly the greatest tragedy to come out of this entire thing is that the work being done on the extremis enhancile will now be shelved for another ten, twenty years because everyone is freaking out about it. With this type of nanotechnology, world hunger could have been eliminated in less time than everyone’s now, instead, going to spend freaking out about this—I can see you think that’s crazy.”_

Actually, Hale looked like he was having a dream come true, the celebrity ex-CEO of Stark Industries fucking up beyond belief _on his show_ , and he made little mollifying gestures indicating Pepper should keep going, even though she’d already just kept on talking. _“Extremis would have allowed us to overcome the limitations of the body: disease, old age, so-called human limits. In_ two years _—which you might say is ambitious, but_ it would take less time than you’d think _—everyone on this planet could have had extremis, and it would be a_ _gift_ _. This is a game-changer, and this set-back may have slowed it down, but eventually we as humans will have to embrace this technology. It’s not a plague. It’s the future.”_

Far away: Steve was starting to look concerned. Tony opened his mouth to say something, and then shut it again. If SHIELD cut the broadcast now, they would—no. SHIELD wouldn’t cut the broadcast now. There was not a single damn ‘accident’ that they could have now that wouldn’t send the entire media up in flames. He should say—something—

Hale looked over the moon. _“That’s a pretty radical view, I have to say. I mean, there’s a body-count for this thing, and it’s not small—”_

“ _Tony wanted to get out of weapons technology because he didn’t like feeling responsible for the body count,”_ Pepper cut across him. _“I told him no. I still think he was wrong—what we had then was an criminal cutting through the system. If not for Obadiah Stane, we would still have weapons contracting as our main line, and frankly, considering the situations that our soldiers in combat zones face, yes, I think that was the wrong decision. But it—”_

“—Tony!” Steve snapped, and half of his attention pulled away from the show and back to his physical body.

“What?” he half-snarled back, while in his head—

“ _Obadiah Stane? Let's be clear, Pepper, are you saying—”_

“ _Obadiah paid and arranged for the hit on Tony that resulted in his capture in Afghanistan in 2008,”_ said Pepper, and Tony felt the words like a punch in the gut.

She’d just—given it away. To the whole world. Just like that. The one secret he'd kept back, even when he shouted everything else from a podium, because he hadn't wanted to admit it—because he'd trusted Obie, for decades.

_I should have cut the feed. I should have cut the damn feed—_

He’d brought this on himself.

“Report,” said Steve. “What the hell are you looking at?”

“Pepper,” he said, somehow managing to keep his voice from catching. Bruce and Jane, who had clearly been expecting some sort of mathematical or scientific problem to be occupying his brain, both sat back; it wasn’t quite a recoil. Natasha’s attention, however, became somehow more total, shifting from viewing him as a _target—_ which, fair, he’d earned—to _puzzle_. “She’s getting interviewed. Live.”

“She’s not cleared for media contact,” said Natasha. “Surveillance should have stopped her, or at least cleared it—”

“Get me media relations,” snapped Hill into her earpiece. “I need an immediate evaluation on—”

“Fox. Yeah, you’re too late,” said Tony, closing his eyes. The interview continued to play out in his head—he wanted to shove it away, but he couldn’t bring himself to tear his attention from it.

“Kinda impressed she managed to slip that one by her surveillance,” Clint remarked to Natasha. “Wouldn’t have thought it of her.”

“She’s resourceful,” said Natasha.

Resourceful. And angry. He could see it now, the way that her fingers moved when she pushed hair away from her face. All her grace, all her poise, was the exact same mask she’d worn for years, whenever she had to deal with—well, him being a jackass—or pushy reporters, or anyone else being out of line. Tony couldn’t look away, even when her hands started to shake, and her voice raised, and her flush deepened. Her hair kept coming loose, and— _christ_.

What was she doing?

The answer was obvious on the stage, and yet—yet—she was reaching a pitch that was getting described as ‘shrill’ all across Twitter, and—

_This isn’t supposed to be her!_

“Tony,” said Steve, “Stop watching. Focus _here._ ”

 _#starkgate2_ was beginning to trend on Twitter—a far more neutral term for it than _#bitchofdeath_. Somebody had started linking macros—the interview wasn’t even _over_ yet, that was fast—based on an image of Pepper leaning forward, her jaw ‘shopped to look like it was half rotting off— _In the future, we’re all zombies,_ said one, and another, _Don’t you think I’m pretty?_

Tony disabled the watchdog program, backed off his link into the feed, and scrambled to his feet. “I’m going to go—lab.”

“Tony...”

“It’s off, it’s—fine, it’s—I just have a fucking idea, leave it,” he said, not looking back over his shoulder as he stalked out.

He didn’t need the armour around him to go invisible, but the only people on this level were those who had been invited to the commissary pizza-party. He shouldn’t _need_ it—

He didn’t, but he sure as hell wanted it.


	15. Weapons of Words: 3.4

They sent Natasha to talk with Pepper. Steve would have gone with, but Tony still hadn’t emerged from his locked lab, where—according to the security cameras, and verified at least temporarily every time Steve stuck his head in the door—Tony had been sitting on the floor for the last four hours, head tipped back against the extremis cabinets, eyes closed. Natasha had been the one to rescue Pepper when she might have been handed over, and maybe that would count for something. Maybe she would manage to convince Pepper to—well, probably not to come in, but to get help, something. Steve had watched a replay of the interview, and she didn’t look well. Her eyes had looked less bloodshot when Clint and Natasha had first found her after months on the run.

They were lucky she hadn’t told the whole world that Tony was alive, too.

SHIELD was stirred up like a hornet’s nest over the whole thing. Pepper’s security detail had all been re-assigned, and twice the number of previous agents assigned in their place. At this, her lawyers had sent over a lawsuit. Thankfully, the security breach didn't fall under SWORD’s remit, and therefore Steve didn’t need to make the calls on a legal case involving a friend.

Steve stopped outside Tony’s lab and stuck his head in for the fourth time that... well, he supposed it was technically morning, now, although the morning papers wouldn’t be out for a few more hours. Tony was still sitting motionless, eyes not even flickering beneath his eyelids. If he was looking at the interview, Steve had no idea.

But he’d said he’d stopped, and Steve had to trust him with that, since Tony was forced to trust him, every moment of every day.

“Captain?” a voice called.

Steve turned away from the door, nodded to the agent standing across from it, and turned to the person who’d called. “Yes, Dr...” He wasn’t wearing his name-badge pinned to his lab-coat’s front pocket, like the scientists were supposed to—ah, but he had it hanging near a button a bit lower down. “...MacLain?”

“Uh, we have an idea. With the rings, the Mandarin's. Would you mind?” Dr. MacLain pointed vaguely in the direction of the elevators.

Hmm, and what were the odds that the occupants of lab four had been up all night and were all now sleep-deprived and halfway to crazy? Steve wanted to sigh—catching some shut-eye himself sounded appealing right now—but better that they were asking for permission than forgiveness. He nodded, and gestured for MacLain to lead the way.

“We need to activate them,” MacLain said, as soon as the elevator doors closed behind them.

Right. Why was that somehow not so surprising? “You haven’t even had them for a day. You can’t have hit a block this fast.”

“They are hunks of rock set on metal. There’s nothing special about them.”

“The report from 3490 didn’t help?”

“No,” said MacLain, not interrupting him, but only barely. “They’re completely different. According to that report there should be energy readings, all sorts of them, but ours don't show _anything._ Cassandra—that is, Dr. Waller—she actually went and started building little fake rings from regular gemstones, and they read the exact same as the ones in containment to every test we can do. If we want to get something, we need to turn the rings on. Right now... we’re actually not sure they’re not fakes.”

 _Damn it,_ Steve thought, feeling his heart sink. The person who had taken the gems off of Borjigin was Toni, and she’d been the one to give them the information on her world’s rings, too. But the idea that she’d betrayed them didn’t make sense, not after everything she and Other-Steve had done to help them. Maybe it was just that the physics of their worlds were so different that 3490's readings were useless. That would still cause problems with the alliance.

The elevator door opened and they stepped out, turning down and into lab four. Steve eyed the set-up. Each of the rings had been locked in one of SHIELD’s heavy duty secured cases, although presumably they could somehow get their scientific readings off them from inside there.

The ring types hadn’t matched up exactly to those listed in the 3490 report, but it was better than having no guess at all. Steve crossed over to the one labelled ‘right, middle’, on the grounds that the ring that could control winds was hopefully the least dangerous out of a set that contained a ring that could disintegrate things, and rapped on the steel case. “Open it up.”

“We need a hand-print from a Level Seven or—”

Steve held up his hand. He resisted the urge to wave. “I qualify.”

“Right. Um... here, then.”

He pressed his hand against the glass table that one of the other scientists wheeled over, and the steel canister split open in the middle, the top half rising towards the ceiling. Sitting innocently on the flat expanse of the bottom half was a gold band with a small blue gemstone embedded in it, sized for a man’s middle finger. Steve picked it up, gingerly—and froze. It felt familiar, somehow.

It _felt_ familiar, a sense that he couldn’t pin down to touch.

“Uh, Captain?”

“Where’s the replica?”

There was a scurrying about—none of the other scientists were doing anything other than watching the show, now—and somebody produced another ring. It looked identical. He closed his eyes, and weighed them both in his hand, rolling them around between his fingers. Then he cupped his other hand over and shook them, so that there was _definitely_ no way he should know which was which.

“Uh, Captain, if you mix those up we really can’t tell them apart...”

Steve opened his eyes, and his hand, and stared down at the rings lying on his palm. They looked identical. There was nothing different about them in any way—but the one on the left was just a gaudy ring with a stone. The one on the right had power.

He handed them both to MacLain, who raised his hands and said, “Woah, no, Captain—I can’t, uh, no—”

Steve raised an eyebrow.

“I am not turning that on in here,” said MacLain firmly.

“I thought you wanted to turn it on.”

“Under controlled circumstances!”

“Focus on not turning it on, and don’t put it on your finger,” said Steve—patiently, because this might _not_ have been his most sane idea, and yet, he _knew_ , somehow... “I’ll knock it from your hand if it’s a problem.”

“Hell, Bill, if you won’t do it I will,” said a watching scientist, which seemed to push MacLain at last to hold out his hand.

Steve dropped the rings onto his palm, and waited expectantly.

MacLain stared at the rings, and then relaxed when nothing happened. He looked at Steve, and his expression turned to confusion. “Um?”

“Which one is real?” Steve asked him.

“I have no idea.”

He couldn’t feel it? Why _not_? It was faint, sure, but it was so familiar. He knew it... had used it. Carefully, Steve picked them both up from MacLain’s palm—the scientist looked slightly disappointed at that; had he been wanting to use them after all?—and raised his other hand to his comm. “Tony, I need you to come take a look at this.”

“ _Really?”_ came the response after a second.

“Yes, really.”

“ _Fine.”_

Steve gestured to the other columns. “Start opening these up, I want to check the rest.”

By the time Tony got there, his watcher trailing behind him, they’d opened up five more. They, too, felt like that same familiar power. “Tony.”

They were getting open stares, now, and Tony’s shoulders were stiff; when he nodded acknowledgement, the motion was wooden. With a start, Steve realized that this was probably the most people that Tony had been around, visible, corporeal, and un-armoured, since he'd surrendered to SHIELD—ninjas excepted. Steve raised his voice. “Okay, everybody out.”

“Goddamnit, this is _our_ lab,” somebody grumbled.

“ _Out._ ” He snagged MacLain, who was beginning to shuffle reluctantly away. “Not you. We need the rest of the rings.”

“...why is Bill always the lucky one...?”

Tony’s minder vanished, too, leaving him to Steve’s custody. MacLain did not look thrilled about this, and Tony, although a bit less stiff, didn’t look thrilled either. “What’s this about, Steve?”

“Here,” said Steve, and passed him the first ring they’d got out, along with its duplicate.

Tony took them without question, and stared blankly at them. Then he said, “This one’s the fake,” and handed that one back to Steve.

Steve took it without question, and kept waiting. Tony’s gaze had gone far away, again, seeing right through his own palm. It was possible to practically see it slotting all together in his head.

“You’ve got the rest?” Tony asked abruptly, and Steve handed them over, and finished unlocking the last four. Tony nodded as he took them, eyes still distant. “Yeah. That’s all of it.”

“You think it’s the same thing,” said Steve.

Tony’s eyes cut to MacLain, and over the comm, he said, _“An infinity gem? Yes.”_

“3490’s notes are pretty clear that it’s not.”

“Maybe it’s not, there,” said Tony, and, _“But not a Prime Gem, I think, just a reflected one. I can test that, I think, if I put it back together.”_

“You can do that?” Steve’s eyebrows rose. They had only just realized it _was_ an infinity gem—and they could still be wrong about that.

“ _Space Gem. I’ve actually already done it, once.”_

“In the Gap. I thought you needed—”

“No, that was just because it was scattered all over. Here they’re already... well, here.”

“Am I supposed to be here for this?” asked MacLain, looking half like he wanted to run for the door and half like he wished he’d kept his mouth shut and his feet glued to the floor.

“You can go, Doctor,” Steve told him, and he made a disappointed face, but went with an air of relief nonetheless. Steve waited until the door shut behind him, leaving them alone in the lab, and then said, “We need to know if it’s the real one or a reflection.”

“They’re both real, Steve. And they both have a crapload of power. I put this thing back together, it’s going to be dangerous either way—dangerous enough to make trying to break it again very stupid.”

“It’s already dangerous.”

“ _More_ dangerous.”

“Tony.” Steve raised an eyebrow at him. “I _know_ the risk. I recognized it too.”

“You get to explain this to Fury,” Tony muttered, and reached out his left hand to the side. It vanished into a wave of black light, not quite a portal, and when he pulled it out again he had the Space Gem in his hand. “Fine. Let’s see...”

Steve had half-expected the gems to fly off the rings they were embedded on, but instead, the first thing that happened was that all the rings flew into a tiny clump in the palm of Tony’s hand. They hung there, a shivering piece of metal and stone, each circular shape starting to warp, fusing together... or, Steve realized, not exactly fusing together. Overlapping, rather. Like each piece was moving to exist all in the same place at once. The metal started to glow, first cherry-red, then brightening into white-yellow, but the glow wasn't from heat. Their shapes were changing...

“Yellow,” said Steve. “Reality.”

“Yup,” said Tony. He sounded strained.

“You okay?”

“This is complicated, shut up.”

Steve shut up. Tony’s eyes were starting to do that blue-and-glowing thing again, and he’d gone pale. Should he tell him to stop? But then the last bits of the rings still sticking out seemed to snap into place, transforming from a misshapen clump and into the same smooth shape as the other gems. Tony’s eyes flew open, and he yelped, dropping the newly-formed gem.

Reflexes had Steve grabbing for it; he barely stopped himself in time. The gem hit the floor, bounced a bit off of the tile, and lay there, shining faintly beneath the harsh institutional lights.

“Wow, okay, that one’s dangerous,” said Tony, crouching down but not reaching to pick it up.

From the report that 3490 had given them, the reality gem was actually the most limited of the set on its own—it needed the others function properly. But once it _had_ the others... “You’re keeping the Space Gem,” said Steve. “We’ll keep this one elsewhere.”

“Good idea,” said Tony, eyeing it. “You still want me to test if it’s Prime or reflected?”

“Yes.”

Tony sighed. “I was afraid you’d say that.” Black light surrounded his hands at the wrists again, and the armour flashed over his skin. Layering up.

“Should I be backing up further?” Steve asked dryly, but Tony shook his head and picked up the reality gem between thumb and forefinger—a marked difference between how he was holding the Space Gem in his closed fist. The black light went out, but other panels flipped open along the armour, and then—

There was a crack, and a sort of grating whine, like a claw down his spine or nails down chalkboard. Tony seemed to blink in place, gone and back so quickly that Steve wasn’t sure he’d actually vanished for that brief moment, and then in the next instant Tony had tossed the reality gem away and was flying straight at Steve. Steve ducked his shoulder, pulled his shield, and let Tony catch him in a flying tackle, bearing them behind one of the thick steel containment pillars—Steve angled his shield above both their heads for further protection.

For a heartbeat, there was no sound.

Another second passed.

“ _Uh,”_ said Tony. _“Okay, I may have over-reacted there.”_

“Be sure about that,” said Steve, not moving; he’d seen grenades go off a second after some unfortunate soul had figured it was a dud.

There was quiet, as Tony ran whatever scans he needed to. After another half-minute, he reached out and put the Space Gem back into subspace, then stood, disentangling them and hauling Steve up with him. _“Yeah, okay, I’m sure.”_

He didn’t sound embarrassed, but on the other hand, he was also still wearing the armour. Steve had seen Tony’s approach to scientific testing before; an over-reaction in favour of safety was definitely an improvement. He patted Tony on the shoulder. “Good reaction to have, something like this.”

“ _True enough,”_ Tony admitted, and started letting the armour fade away. “It’s the reflected gem, all right. It definitely wasn’t fond of the idea of leaving this reality.”

“Uh. Is it sentient?”

“I don’t think so?” Tony ran his hands through his hair. “I don’t know, I’m not the guy for debates on alien sentience.”

3490’s report had mentioned that a soul gem could have... _desires_ , something Stephen Strange had told Steve explicitly, but the implication had been that the others didn't. On the other hand, if they were all reflections of the true thing, then maybe this one had a reflection of different aspects... just as, according to Tony, Asgardians did. “The Space Gem isn’t sentient, is it?”

“No,” said Tony. “There’s a difference between sentience and... design is the wrong word. Or maybe not.” He made a face.

“Okay.” Steve let himself contemplate the corner that Tony had thrown the reality gem into for a moment longer, and then marshalled his thoughts. “We can lock it in one of the containment units here for now. Can you keep an eye on their security?”

“Uh-huh. I reiterate: you get to explain this to Fury. This was all your idea.”

Steve patted him on the shoulder again, and went over to grab a broom and dustpan that had been left against one wall. He didn’t want to touch the thing, if he could avoid it. “Don’t worry. I’m sure he’ll be happy to blame me.”

“Sure he will,” Tony muttered.

Just in case, Steve left Tony back at the NYHQ and flew out alone to make the report to Fury. He ended up cooling his heels on the Helicarrier for nearly an hour, ostensibly waiting for the Director to get out of a late-night emergency meeting with the WSC. Given Fury's reputation for omniscience, Steve might have ascribed it to punishment-in-advance, but when he finally got waved in to Fury's office, there was a distinctly pleased gleam in the Director's eye, and an air of benevolence about him as he listened to Steve's report.

At the end, Fury accepted the small, highly secured black box that Steve handed over, and told him, “Good catch. Next time, don’t make such a production out of it.”

“Sir.”

“Unfortunately, it doesn’t solve the problem of where the real one is.” Fury steepled his fingers and leaned back in his chair. “But now you’ll have help. The Council has, at long last, agreed to initiating contact with a dozen of the Earths our scientists picked out, as well as assembling two other Gaterooms.” Since Steve knew damn well that those Gaterooms were pretty much assembled aside from being hooked up to a reactor for power, that was probably a good thing. “Continued close contact with 3490’s also been approved.” Fury tapped a sheet of paper and slid it over to Steve.

That explained the good mood. And was definitely worth waiting an hour or two. “3490 needs to be a priority, sir. They’re the most advanced world we’ve discovered.”

Fury nodded. “Make it happen.” As Steve rose to go, he added, “And Captain? I'm glad you decided to trust me with this one.” He tapped the top of the black box.

Steve felt the back of his neck burn, but he held Fury's gaze. At the time he'd had good reasons to not tell anybody about the soul gem. For one thing, everybody had thought he was going crazy, even _without_ going on about a soul-stealing gemstone. For another thing—

“I don't think the Council needs to hear about it just yet,” Fury finished.

Steve gave him a thin smile. “Didn't expect you would, Director.”

 

* * *

 

Natasha left Pepper’s place at dawn. Outside, for the briefest moment as Natasha paused in the street, there was an expression of confused frustration on her face. Then she smoothed it away. Tony felt a twinge of guilt for spying, and took his attention away from the satellites as her car drove off.

He locked the door on his lab, hacked the cameras so he could fill them with fake data in real-time, and set up a modified Foster Silencer so that his minders wouldn’t hear him leaving. Not that that would help much on the other end. Unless... he reached into the subspace pocket and pulled out the Space Gem.

It didn’t do a damn thing for searching, but he knew where he was going, here, how the pieces fit together—him, Chicago and Pepper’s apartment, the rotation of the Earth. From moving pockets of air bubbles around, the next logical step was to be able to move himself. Well, there might have been a few more steps in between, there, but—running, flying, walking. It all came down to the same thing in the end.

The person who’d have told him otherwise wasn’t around anymore.

Tony popped into Pepper’s hotel-suite living room just as she was pouring herself a third mimosa at the kitchenette. She’d left her makeup on for Natasha’s visit, and superhuman vision let him see where it would need a touch-up soon. She must have already done one touch-up on it before Natasha had gotten there—it had been smudged, by the end of her interview.

She looked up, saw him, and jumped. Half the mimosa slopped out of the glass and over her hand, dripping toward the floor, and for a moment, the expression on her face was the exact same as the one she’d worn eighteen years earlier, the first time she’d walked in on him _in flagrante_ with a model in the kitchen, back in the Malibu house—shocked, appalled and clearly on the edge of her patience, but still so put-together...

Then it vanished, and Pepper was reaching for the napkins and cursing, and Tony jumped forward to help, grabbing the napkins to wipe up what had spilled down to the floor.

“Oh, back off,” she snapped, as they nearly bumped into each other reaching for more napkins at the same time. Tony held up his hands and took a step backward; Pepper took a long drink of her mimosa, and went back to wiping the rest off of herself and her dress—the dress, really, was a lost cause. He winced.

“What the hell are you doing here? I’ve been getting the third degree from _Natalie_ for hours, you can ask her for details.”

“I—” His mouth wasn’t dry, he’d written a program to fix that problem. Why didn’t it fix the problem of not knowing what the hell to say? “Why?”

_Obie’s been dead six years, why did you drag it all up now, why did you_ give _them all of that?_

_Why lie? Which one_ was _the lie?_

“Why?” She threw the damp napkins in the sink, and slammed down the glass on the counter, glaring at him. He wondered what her face looked like beneath all that makeup—when was the last time she’d slept? Her eyes were red. “That’s _rich_ , coming from you—”

“I told you damn well why,” he said sharply, “There was nothing you could do, and it would make you a target.”

“Oh, because not telling me anything kept me _safe_?” She laughed, harsh and disbelieving, and it was the same conversation they’d had before and— _fuck_ , he hadn’t expected this. He’d known he was being an asshole but he'd thought that if he could keep her out of it, it would be worth it, for the chance that before they all died screaming Loki wouldn’t come after her personally, and _yet—_

“Christ, Pepper,” he said, looking away. “I—I’m _sorry_ , okay? I wasn’t—I didn’t... deal well, with that—”

“When have you ever? All my adult life I’ve had to _manage_ around you,” said Pepper. “Even after you gave me SI— _tricked_ me into having it, damn you—you always had—you did whatever you damn well pleased and left me to clean up the mess and cover it up. But when I _asked—_ no, none of that mattered then.”

“I wanted to keep you safe,” Tony said, quietly. He couldn’t seem to manage any louder volume.

“You were a moron.”

“Obviously.”

She turned, motions jerky, and grabbed the bottle to top off her mimosa with another shot of alcohol. “So, what. Now you’re going to just stroll in here and—spill? Give me insight into the great mind of Tony Stark?”

She was acting—erratically. Off.

Christ, hours ago she’d told the whole world secrets that were supposed to be years buried, and the things she’d said—his decision to shut down weapons production, the goddamned way she’d spoke about extremis—Jesus, it would never have been ready in _two years_ anyway, and to call what had happened in Shenzhen a _setback..._

Steve would tell him no. Would tell him that Pepper needed counselling, but... Steve would bench her just as fast as he’d benched Tony. Probably faster; Steve actually learned from his mistakes. Apparently it took Tony more than one go.

“Yeah, that’s what I thought,” Pepper said, and downed her glass in one go. She set it aside and stared at him tiredly. “It’s not _your_ idea anymore, right? It’s SHIELD’s. You son-of-a-bitch. You’re finally dancing to somebody else’s tune, just in time to screw me over.”

“Pepper...”

“I’m going to bed,” she cut him off. “See yourself out. If you ever get that collar off your neck and your head out of your ass... well.” She looked at him sadly, and there was something else there, too, that he had no idea how to interpret. “It’s fixable, Tony. It’d take less time than you think. Don’t come back before then.” She turned away, headed for the bedroom, her hands fumbling with the buttons on her stained blouse.

He’d long ago lost the right to see her like that. Tony tightened the radius of the silencer, and teleported himself back to his lab.

 

* * *

 

Setting up alliances with other Earths was... chaotic.

Their second approach to another world—their first _intentional_ approach—went disastrously wrong. For this trial run, the WSC had insisted it be a slightly lower-tech world than their own, but that meant no one there had ever interacted with people from an alternate reality before. There was no single world government, so they'd dropped the SWORD team near the other world's UN headquarters, and within hours the entire team had been arrested by the NYPD and thrown in holding cells pending psychiatric evaluation.

The agents had been crimson with humiliation when Tony had retrieved them, portalling back into the NYHQ with an ear-shattering _boom_. In their defence, they were pretty junior agents, none of them with clearance beyond Level 4.

Steve was sure that Fury had set the entire situation up deliberately, because after that they got the green light to contact higher-tech worlds, ones with experience or at least knowledge of alternate realities. 3490's help was invaluable there: they had a whole catalogue that was far more extensive than what SWORD had been able to put together. And most of the worlds they were familiar with had Avengers. Steve went offworld a few times, played tour guide, and tried not to become frustrated with the WSC's continuing paranoia about signing treaties, asking for technical help, or even just revealing the true threat that was out there. He spent a lot of time ranting about the Council to Tony, while Tony zoned out with extremis and said soothing things like, “Mm,” and, “Yeah, they're assholes,” and, “That's nice, Steve.”

When he asked in return what Tony was working on, Tony said, “Efficiency algorithms.”

“For...?”

“Extremis. Toni's ideas gave me some ideas, efficiency's not just about energy usage—” Tony spent a good hour more going into detailed math about it, none of which made any sense to Steve. But despite the fact that most of the science Tony worked on didn't make much sense to Steve, or to anyone who wasn't a super-genius, Steve wasn't quite sure that it wasn't just snow, this time.

That probably wasn't fair. The lack of action on SWORD's part was just making Steve antsy. With the partial cure that Gaia had offered, Leo and Dr. Kafka had agreed that Tony was doing a lot better, although they cautioned that he was still suffering from paranoia, still obviously hiding things. The question of Tony building weapons again wasn't raised. Remembering the terrified voices beneath the Temple of Winds, and the lightless wasteland that Maklu had been reduced to, sometimes Steve wondered if he'd been wrong to push him out before—even though Tony couldn't have kept going as he was, _shouldn't_ have for his own sake.

But there was a sense that he hadn't had before, that they were running out of time. They were starting to make progress, but it was all too slow.

Two weeks after they'd rescued Tony, Steve watched on the monitors as a single one of Thanos’ black ovaloid ships hung in high orbit above Earth 294010.88 and rained death down upon it. 294010 had been the tenth pick on their newly-approved list of worlds to contact. It was a solid choice: stable world politics, less advanced weapons technology but much better communications, and it had had very public contact with its Asgard, so both civilians and world leaders knew that aliens existed.

They'd opened a window to it five minutes ago to discover that what had been a prosperous world was quickly becoming a smoking ruin. Most of Europe and Africa was already reduced to char.

Steve hit his earpiece. “Tony. Take a look at this.”

The holographic image of Fury, standing beside Steve, crossed its arms. “It’s too late, Cap.”

“It’s one damn ship. Send a nuke through—”

“We can’t handle the attention we’d get, and that’s final. Shut it down,” Fury ordered the tech operating the viewer. “I don’t want whatever’s on that ship getting the bright idea to look back through it.”

“That’s eight billion people we’re leaving to die.”

“And a lot more will die if we act. We are not _ready_ , Rogers—”

“And whose fault is that?” Steve asked, and instantly regretted it.

Fury’s image flickered as he stepped in close to Steve. “Think very carefully before you start parcelling out guilt here, Rogers.” He leaned back. “I want those images on my desk ASAP. They’ll be going to the Council. Now, I’m sure _everybody_ here has something _constructive_ they could be doing.”

“Sir,” said Steve, and was echoed by the rest of the techs and scientists in the room.

The viewer finished shutting down, and the techs began to program in the next world, 391414.14. Over his comm—tapped into half a dozen channels—Steve could hear other conversations. Security questions, primarily. They had a hell of a lot of ‘aliens’ wandering around HQ, and a few more up in quinjets, getting a look at Earth—wariness went both ways. But there was only silence from Tony, so far.

“Tony, report,” he ordered, stepping down from the viewing deck of the Gateroom and heading for the elevators. When that still got him no response, he flipped the channel to the general security. “Prajaprati, check on Stark.”

“ _Door’s locked,”_ the answer came back, unhelpfully, a moment later.

 _Damn it, not again_. Steve lengthened his strides for the elevator, and jammed the button, frowning—then jumped and nearly broke his hand on Tony’s armour as his invisibility cloak rippled off _right next_ to Steve. He checked his swing at the last second, and pointedly rapped his knuckles against Tony’s faceplate.

“ _Sorry,”_ said Tony.

“Thanos is attacking 294010.88,” said Steve, dropping his hand to his side. “Can we—”

He stopped, then, because Tony was already shaking his head.

“ _I took a look,”_ said Tony after a moment. The armour’s voice was muffled, hollow. _“There’s weapons that could punch through a ship like that, but they had an open wormhole behind them. Take down one, more would come.”_

“But there _are_ weapons that can fight this—and you have them,” said Steve, his eyes narrowing.

“ _WMDs, yes.”_ The elevator arrived, and they stepped apart to let a trio of scientists off. All three women shot them nervous glances over their shoulders, and Steve made a conscious effort to relax his posture and smooth his expression into neutrality, gesturing Tony further down the side hall leading from the elevators. Tony just switched to speaking over the comm instead of out loud. _“Those were scouts, foot soldiers. You saw the way that Thanos reduced Maklu to shreds just by showing up. We can’t afford to get distracted, here.”_

“Tony. People are dying.”

“ _You think I don’t know that?”_

“If there’re weapons that can stop those scout ships and save an entire world—”

“ _And then what?”_ Tony didn’t lean in: he stepped back, shrank away. _“We need to kill Thanos. This stops when he does.”_

“It’s not good enough to just stand by in the meantime—”

“ _You really don't know what you're talking about, Steve. There's nothing I have that can stop Thanos. Meanwhile, I bring out weapons, it’ll be a bodycount just as—I’m not doing it. I won’t.”_

“This isn’t like that,” Steve bit out. This was not _Pepper_ , this was not Obadiah Stane, and this was not Stark Industries. This was people dying by the billions and left undefended by somebody who _could_ defend them—maybe not from Thanos, but if Tony could buy them even a few more days it would be time to save somebody, evacuate _some_ of them, somewhere—

“ _It’s exactly fucking like that,”_ said Tony, and vanished—whether by teleportation or into invisibility, Steve had no idea.

“Running away?” Steve asked over the comm. There was no answer. “God fucking _damnit!_ ”

He couldn’t—he had to—helpless rage was making his head swim; he punched the concrete wall, and then again, until the knuckles on his right hand were bloody, and then he stared at the red stain he’d left and realized that somebody would have to clean it up, his hand hurt, and he was still angry. The hallway was almost conspicuously empty.

But he could, at least, think a little more clearly. They needed to be able to evacuate people on worlds under siege—that meant they needed a method of massive transport, and somewhere to put them. The logistics of the problem were staggering, which called for a non-conventional solution. They needed a way to fight back, without using Tony’s proposed weaponry... but they knew of three alternate counterparts of Tony, now, and more scientists also skilled at making things that made really big explosions. They needed to get all the worlds they’d contacted already in on this—maybe Tony thought it was getting distracted from the ‘real problem’ of Thanos, but, hell. If they couldn’t manage this, then they needed to pull in more people.

SWORD was still too much under the WSC's thumb, and this was the result of all their delays. It was time to start pulling on the leash. 3490 might or might not help—they hadn't started reaching out to other worlds on their own yet, which SWORD's analysts thought meant 3490 had its own reservations about the whole plan. He wouldn't know until he asked. He thought that the other Steve and Toni were decent people. He thought they would help.

Steve stretched his hand—the skin was already healing over—and winced. He pushed the elevator button again, this time for up. Building services was located in the regular basement, high above the various sub-levels. On the way up, he could think this problem through.

And try not to think about how disappointed in Tony he felt.

 

* * *

 

When Steve calmed down, the plan of attack was obvious.

Tony wouldn't help. It sat in Steve's gut like a red hot coal, but treating Tony like he was the only person with a solution was the exact same thing he'd been trying to prevent _Tony_ from doing a month earlier. Bruce and Jane were in charge of the Gaterooms, and both of them were horrified at what had happened to 294010.88. Natasha and Clint were Steve's left and right hands when it came to security. If Steve wanted records to vanish and portals to open without being logged, all he had to do was ask.

They were bound to get caught out eventually, but not in the two days it took to set-up an inter-reality briefing.

“If we’re going to stop Thanos from killing Earths, we need to allow them to defend themselves,” said the Captain America of Earth-40727.32, who had yet to take off his cowl or even give his real name, but who preliminary observation had confirmed led a team of Avengers with the full approval of and a signed charter from his president. “I get what you’re saying about the risks of alternate Earths—there’re a frightening number of fascist ones out there—but frankly, I’m _appalled_ that you’ve known about this for so long and have been keeping it from everybody. This is something that every Earth deserves to know, and if you’re not going to spread the word, then we damn well will.”

“So what are you saying? We start dropping pamphlets? Most Earths don’t even know about alternate realities,” said Captain Britain-1058.93, before Steve could answer. “This is still going to take time.”

“We can help with that,” said Sue Storm-6590.01. She nodded to Steve. “I understand that you’ve been handicapped by your political structure, but we don’t all have that disadvantage. There are representatives of nearly twenty Earths around this table. Some of us will be able to throw more manpower at it more easily than others.”

“We moved slower than we should have,” said Steve, nodding to Sue and meeting Captain America-40727’s eyes. “I know. Believe me, I regret it.”

“Our world can coordinate warning others,” said Sue, which drew more or less universal agreement. It seemed Sue Storm was respected pretty much everywhere, and 6590.01 was one of the most advanced worlds that had answered their call.

Fury would tear a strip at him when he heard about this part in particular, but they were right: the WSC had handicapped SWORD. Eight billion people were dead; the WSC could go hang.

“The second problem is defence,” Steve said, after waiting a moment to see if anyone else was going to chime in on that topic. “Tony got a good look at the ship that destroyed 294010, and has downloaded his scans to the tablets we provided you. But those are just the beginning. Among ground troops... some are Chitauri. A lot aren’t. The after-effects of the weapons we saw in Maklu aren’t pretty, and when Thanos himself got close...”

“Time and space warped,” finished Sue, nodding. “That’s something that the scientists among us are going to have to figure out, I’m afraid. But for initial strategy we can focus on more conventional defence and offence.”

“You’re talking about—what, a space fleet?”

“It can be done.”

“We will build it,” one of the representatives towards the other end of the table spoke up—a silvery, androgynous person from Earth-89772. That Earth was one of those that had been recommended by Earth-3490—Steve didn’t think there was any way that the WSC would have cleared the Androids , who, from everything that had been observed, were the sole sentient race upon their own world. But their technology was probably the most advanced of all the Earths represented at this table. “We excel at such things. We may ask assistance of you, however.”

“You’ll have it,” Captain America-40727 promised, simultaneously with several others around the table. Steve wished that he could have joined them.

“The most conventional strategy that we non-geniuses can do is go looking for allies.” That was Janet Van Dyne-3490, attending in place of Toni, who was apparently buried in her workshop, and Other-Steve, who was readying that world’s defences. From what Steve had been told, Van Dyne was one of 3490’s most respected superheroes, who apparently fought crime by... shrinking down really small. 3490 seemed to think it a viable tactic. “We’ve set a few teams of our own to this Prime reality. I’m sorry to report there’s been no word back yet.”

Steve shook his head. He'd known that 3490 was working on their own solutions, but as hypocritical as it was, he wished they'd given him a heads up about _this_ —mostly so that he could have warned them in more strenuous terms. “It's directly under siege from Thanos. It’s dangerous as hell.”

“Since when has anyone here flinched at danger? From the information you’ve given us about how the cluster of multiverses fits together, it may be we can’t impact anything by staying in our own realities. If we’re going to take down Thanos then we’re going to have to do it in the Prime reality. That means knowing what we have to work with.”

“We know what at least one god wants to work with,” said Captain Britain. “The Infinity Gems.”

“And we know that other gods have dismissed them as useless.”

“Still worth a look.” Captain Britain tapped the table. “This is probably one of those things we need the geniuses to debate. Many of us know where the infinity gems are in our own realities. Can we use them to triangulate the Prime versions?”

That was... the Chief Magistrate had asked for the soul gem from Steve. If she’d had the Prime version, it shouldn’t have mattered. If she’d _not_ had the Prime version, why would a reflection matter, if she couldn’t use it to find a Prime version? But then, Maklu had existed as the same world across all realities, connecting them all at the centre of the cluster...

He’d missed something, he realized, as he was suddenly confronted with half the table looking at him expectantly. Steve blinked, his immediate memory recalling the words to his conscious attention—Captain Britain had asked to see the Prime Space Gem. “I don’t have it on me,” said Steve, which earned a few dry chuckles—no doubt from the others who had ever carried a gem. “I’ll ask about it for the scientists. Being able to triangulate the Gems is a good idea—” He told them about the Chief Magistrate’s concern for the reflected soul gem that he had had.

“We could try just bringing it into Maklu,” said Sue thoughtfully.

“It has to be more complicated than that...”

“Maybe.”

“This is a discussion we need to leave to the scientists, I think,” said Steve. “We’re here for coordination, this meeting.”

“Then, practically speaking, it’s going to have to be your Earth that coordinates that one,” Captain Britain noted. “Since you’re the only ones who have seen a Prime Gem.”

Not everyone else looked terribly happy about that—Captain America-40727 in particular. Steve ignored that and nodded at her, trying to think of how to lure Tony out of his lab. He could probably just ask him—Tony didn't want to hand over weapons, but this wasn't that. “Your world knows where its full set of gems is, right? We'd need to work with a world that has all of theirs.”

“Not a problem,” said Jan. “Trust me, Toni would love to have you as a guest again.” There was something in her tone that Steve couldn’t quite interpret, but which made several others around the table, including Sue Storm, go very straight-faced. Was she implying...?

He decided to ignore it. “After this meeting, then. Next—”

 

* * *

 

“That is the gaudiest damn thing I’ve ever seen, and I was a 70s kid,” said Tony, staring down at the glittering, golden gauntlet lying on the table.

From the other side of the table, Janet van Dyne nodded agreeably. “Deplorable lack of style.”

“It’s the most powerful weapon in this reality, it doesn’t need much style,” said Toni, and then she held up a hand at the looks the other two shot her. “Ooh-kay, just saying.”

Steve had to admit that ‘gaudy’ was certainly the word for the so-called infinity gauntlet. It might have been a knight’s gauntlet, if it had been made of steel instead of gold, and on the main knuckle of each finger, the thumb, and the back of the hand was embedded a softly shining gem.

“It does more than allow the wearer to use all six gems at once,” said Reed, who was standing on the fourth side of the table. “It puts them together in conjunction. The space and time gems give you the _sense_ of space and time, far beyond the mere ability to move things around within them; the mind gem _expands_ the mind of the wearer itself; the reality gem becomes understanding of _how_ reality is put together—how it can be broken, how it can be changed—and the power gem pulls energy, limitless ability to change whatever is desired.”

He was missing one, Steve noted. “And the soul gem?”

Reed made an expression that looked over-exaggerated on his somewhat extended face. “That one’s a special case. Taken alone, it acts as the counterpart of the mind gem, but in the infinity gauntlet, it more closely corresponds to the reality gem. If the reality gem gives the _how_ , the soul gem, you could say, gives the _why_ —but don’t think it’s any kind of universal _why_. It depends on the wearer. I’ve worn the gauntlet once. I wouldn’t dream of doing so again except under the direst of circumstances.”

“These are pretty dire,” said Toni.

“Dire enough that this infinity gauntlet might not be useful, yes.”

Tony crossed his arms over his chest—tightly, like he was pinning his own hands. “I shouldn’t touch this.”

“Hm,” said Jan. “Give the Space Gem to Steve, then, let him take a look.”

Tony had been very carefully avoiding making eye-contact with Steve all afternoon. Steve shot him a look and found that hadn’t changed. In company wasn’t the place to push it, so Steve raised an eyebrow at Jan instead. “Me? I’m no scientist. Whether or not I managed to do anything with it, we wouldn’t learn as much.”

“Very true,” agreed Reed.

“Well, it’s a bit gauche to ask somebody to give up the Gem from their reality,” said Jan. “Even if it’s not from _their_ reality.”

“It would just be for a quick test,” said Reed mildly.

“Or possibly for a longer one, depending on how it worked out.”

“Okay, enough of this,” said Toni, and she plucked the gauntlet’s space gem off. Immediately, the gauntlet seemed even gaudier, as if it had been reduced from gold to spray-painted tin. “We don’t need the gauntlet for the first test—try it with this.” She flicked the space gem at Tony, who startled backward—it bounced off of his crossed arms and fell onto the table.

“You’ll be fine,” Steve told him.

Tony _almost_ gave him a look in return, but un-subspaced the Prime Gem, and, holding that in his left hand, held his right out over the reflected version. His eyes lit with a faint blue glow. “Huh. Definitely a resonance, there.”

“Yes,” said Reed, snaking his head back and forth between monitors on his suddenly ten-foot-long neck. “I can see that. Getting readings now... hmm. They are very much linked. Do you see—”

“Yes,” both Tony and Toni chorused. Both of them were visibly concentrating on extremis.

“Those are two gems of the same type, but it is the _Space_ Gem, Prime and mirror, that you have there—”

“Great,” said Toni, picking out the reality gem, this time. Losing a second gem didn’t seem to diminish the gauntlet further—apparently, it only had two settings: complete, and incomplete.

More tentatively, Tony held out his hand over that one. Machines started beeping away furiously; Reed stretched out impossibly long fingers to turn the alarms off, and said, “We need at least one more point to decompose this from—more would be better—”

“It’s not as clear as you think,” said Tony. His eyes were half-shut. Reed’s monitors froze for a second, and then data flooded onto them. Toni’s eyes went wide.

“Damn,” she said. “That kills that idea.”

“Maybe not. If we have more gems from other realities—we know enough of them by now,” said Reed. “I think you’re overcomplicating it, Tony.”

“Maybe it just doesn’t seem as simple to the rest of us as it does to you.”

“Test the rest here, at least,” said Toni, prying out the mind gem. “The security on these are such a bitch to bypass, we might as well cover them while we already have them out.”

By the time they were finished, Steve was honestly starting to get a bit bored, and regretting that he’d not sent along somebody else to play backup and escort to Tony. Jan, not stuck in another world, had gone back to the Avengers Tower to help out where she could there. There were so many things Steve needed to be doing... but he’d felt like he was going to burst at the seams if he’d stayed in the NYHQ. Reed’s lab, on an Earth that wasn’t his own, shouldn’t have felt so much more comfortable, but once Reed had remembered Steve was there and offered to set him up with a computer so he could do some work of his own, it turned out to be surprisingly... familiar, almost. In a good way. Or maybe that was down to how Tony had lost the edge in his voice.

“I can start trying to rough out an algorithm to pinpoint the location of the real thing,” Reed said eventually, “but, until we have more data points, honestly, my time is better spent elsewhere. I’m sure that in other realities I will have similar equipment, however—or, of course, you can assemble your own to bring with you.”

“We don’t have time to give this a probability cushion, Reed,” said Toni, moving to flick the six reflected gems into separate boxes, and the Infinity Gauntlet into its own, larger box. She stacked them on the table. “I have to agree, there’s some other signal involved in this mess—location, probably.”

“Well, if it comes to that, we can try taking a reflected gem to Maklu, but you’ll have to be very careful about the trip.”

“With the Prime Space Gem?” said Toni. “That should be the smallest concern.”

“Hmm. It’s true that there’s not much more data we can gather here for the moment.”

“No,” Tony agreed, putting the Gem back into subspace.

“I still want _that_ trick,” said Toni, watching him. “How’d you manage to secure it that tight? Subspace vaults are notoriously easy to break into.”

Tony smirked at her. “Like you said, it’s a trick. But—ah—here, something that’s not such a trick...”

They exchanged glances—email in a glance?—and Toni frowned, then smirked right back at him. “Darling,” she drawled. “That’s so two years ago.”

Tony made a face. “Damnit. I’ll think of something.”

“If we’re done here, we should be getting back,” Steve interjected, swiping the logistics files he’d been working on to the side to download them to his portable drive.

Tony didn’t quite tense, but he didn’t exactly meet his eyes, either. “Yeah. I’ll keep working on it. If you think of anything else with it, Reed, Toni... you’ve got our address.”

“Of course,” said Reed, not looking up from his screen.

They were greeted upon return by a tech with a tablet for Steve; on the screen was a scowling Nick Fury. “Director,” Steve said, reaching out with his other hand to snag Tony’s elbow and keep him from drifting away and possibly into invisibility.

“ _We need you up he_ re,” said Fury, and between the beginning and end of ‘here’, the world blinked and was replied by the command deck of the Helicarrier. Steve found that he was holding onto the sleeve of a stuffy-looking suited agent, the fabric at odds with the metal he could feel beneath his hand. He let go.

Fury, on the other hand, scowled even harder at Tony’s disguise. “I advise you don’t show off too much,” he growled, turning on his heel and heading for his office.

“I haven’t done anything,” said Tony as soon as the door was closed. He was still wearing the illusion of being a SHIELD agent, but it was his own voice.

“Yeah, and the Council’s about as happy with your refusal to make weapons as Rogers is,” said Fury, slapping down his own tablet. He raised a pre-emptive eyebrow at Steve. “And for the record, Rogers, I’m none too happy with you, either. But in any case, _some_ little birdy leaked back that you might have a way to find the remaining Infinity Gems... and that you _shared_ this knowledge with our new allies.”

Damn. Steve had hoped he'd have more time.

“That is, generally, the point of being allies,” said Tony, unexpectedly. Steve only just managed to keep from blinking at him. “Sharing—fine, shutting up.”

“ _Thank_ you,” Fury told him. He returned to glaring at them both. “If you haven’t figured it out already, the Council wants to have those Gems first. And if you find them, it would make it a hell of a lot easier to arrange things so they don't feel the need to bury you.”

“We just spent two hours trying to find the things,” said Steve. “We need more data points.”

“Or we need to go to Maklu,” said Tony. Steve raised an eyebrow of his own. The agent’s face stared back blandly. “I need to go there to check it out eventually anyway. Whether we do it because the Council wants it or not.”

“In this case, I’m inclined to agree with them,” said Fury, going around to the other side of his desk and punching in a twelve-digit key combination—it didn’t make any beeps, but Steve could hear when Fury’s finger hit the glass. “It’s a weapon, Captain—we want to grab it _first_. We can consider giving it away after.” There was the sound of hydraulics decompressing, a door opening, and Fury pulled up a large steel box, setting it down on the desk.

_Three guesses for what’s inside, and the first two don’t count._

“Right.” Steve felt his lips curling up into a thin, mocking smile, one that felt wrong—but, God, they needed to open their eyes. “Like we’ve been so ready and willing to help other Earths against Thanos.”

Tony looked away. Fury, on the other hand, met his eyes fearlessly, and shoved the case with the reality gem towards him. “You are showing a dangerous lack of common sense, Captain. You can’t save anybody from drowning if you go under yourself.”

“Sir.”

“Go,” said Fury. “Now. Try it, and if it works, for god’s sake bring the damn thing back here.”

“Sir,” said Steve, again, grabbing the case and his shield from his back, and stepping to stand back-to-back with Tony.

The shift this time was not quite so unnoticeable as when Tony had moved them up to the Helicarrier. Purple light flashed out, surrounding them and streaming by so quickly that it gave the impression of standing still when he looked at directly. There was a rushing noise in his ears, and a sense of immense distance that, he thought, he could just _begin_ to grasp at—and then they jarred back, his feet were on the ground, and that almost-grip on infinity was gone. Had he imagined it?

“ _Oh_ ,” said Tony softly, more through the comm than through the armour’s speakers.

They were standing at the epicentre of a blast site. The sky overhead was a perfect, uniform blue—unnaturally uniform: it didn’t lighten near the horizon like actual sky did. The ground beneath their feet might once have been rock, or concrete, or glass; it was something hard, naturally rough and yet blasted into a smooth edge, the colour of white ash. Starting at about ten feet away, the first pieces of rubble stretched away from them, having clearly been thrown outward in a circular pattern... of which they were standing in the exact centre.

“ _We shouldn’t stay here long,”_ said Tony. He took a step away, and another. At the edge of his vision, Steve’s perception of the rubble wavered. He glanced around, and saw that the centre of the blast had shifted, slightly, to just behind him. Or—he turned, and saw: it was now centred directly between him and Tony.

“Is this an illusion?” Steve asked.

“ _No.”_

Steve grimaced at that. He wasn’t quite so sure, but Tony was certainly right about one thing: they shouldn’t linger. The air smelled of something dryer than ash. Steve knelt, set the secured case on the ground, and pressed his hand to the top. “Steve Rogers, authorization code 86-92-50-83,” he told it when it beeped.

The top popped open and there was an electric snap—some sort of field inside it activating, perhaps. The smell of ozone wafted out as he lifted the lid. Inside, the yellow gem sat within foam pads; he lifted up the pads rather than touch the thing directly.

“You gonna be okay to do this?” he asked Tony, offering the entire assembly up to him.

Tony paused. _“Here I thought you_ wanted _me to make weapons.”_

“Tony...”

Tony didn’t move. _“It’s your call, Steve.”_

“Then do it,” Steve told him, and handed it over.

Tony already had the Space Gem in his right hand; Steve could see the light leaking past his fingers. He picked the reflected reality gem from the foam and held it up to the sky. Steve, watching, couldn’t see that any light filtered through it—it was still translucent, but its light came from within. Then Tony closed it in his fingers, and Steve felt _something_ , rolling over him, through him—something like wind on a summer’s day, like clarity, like looking up at tree-branches and seeing them perfect, crisp and clear against the sky behind. It was the curve of his shield on his arm, perfectly balanced, a harmonic he could understand and recognize even in his sleep, a symmetry that went past the shape of it and down into the core of the metal itself. It was the symmetry all around them, present beyond whatever the blast had done—the symmetry written into reality itself.

Yellow light burst from between the fingers of Tony’s left glove and he opened it; a bright and shining power fell from his hand, and everything beneath its light looked sharper, jagged and edged. Then it hit the ground and it was solid, nothing more than a Stone lying there.

Nothing more, and nothing less. _Real_ , in a way that Steve knew, instinctively, he’d never felt before.

“ _Done,”_ said Tony hoarsely. _“Fuck. I can’t believe that worked. We need to go. Put it away, we need—we have to go.”_

Steve picked it up and snugged it back into the foam. Light burst between his fingers, and even with the foam around it he could feel the Gem through it, feel its power, the wobbliness of matter and energy around him. God. What must Tony have felt, with the Space Gem clenched in his other hand? And yet, they were all so far behind...

“ _I think I might’ve been seen—what are you doing?”_

The Gem wasn’t in the foam anymore. It was in his hand.

“Override 54,” said Steve, and Tony crumpled like a puppet with cut strings.

 

* * *

 

There was an instant in which Tony didn’t realize what had happened. Steve had been staring at him—and then Tony was enclosed in perfect darkness and silence, and he had no idea what had happened, except that his head hurt like he’d gotten beaned with a pickaxe.

A moment later extremis began to fall away from his body, shedding off in giant flakes, and he could breathe again, and hear, as Steve said, “—something you need to see.”

 _He used the override._ And Tony hadn’t heard it coming. Extremis had disabled his ability to hear it, to react to it—just like planned—but _why—_

“Steve?” he asked, mounting dread growing in his stomach. Tony had been waving a torch around from the centre of the universe, calling for the Reality Gem—had something else noticed? Oh, christ, Steve had just overridden him—what had he been about to do? Had he _done_ it, and forgotten? Had Steve stopped him in time?

“Loki. There’s not much time,” said Steve, _not_ to Tony but to thin air, and Tony—

—didn’t have extremis; couldn’t think any faster than his pitiful human brain—

—flinched away, as green light crackled, and the voice he heard in his nightmares purred, _“Well_ , now—”

He fell.

The Gap closed around him—stripped naked, no armour left, but the Prime Space Gem was clenched in his fist, responding to the sheer mindless terror that that voice evoked. In the Void there was neither up nor down, but Tony fell anyway; there was no ground to stand on, just the cold light of the Gem in his hand. Steve had just—

_Why—_

_Loki_.

Loki must have done something to him. Christ. The shrinks had been over him—Fury’s pet psychic had been over him—but they’d found nothing in two weeks. _Why_ —no, it had to be Loki. Loki had been—Loki hadn’t been after the Power Gem when he'd grabbed Steve. Or maybe he had been... but he had the Mind Gem, for certain. Tony’s thoughts filtered through the Space Gem, and he _knew_ where Loki was—yes, he could sense the Mind Gem, there, exactly where he expected it to be. He could sense Loki's laughter behind it. If he went anywhere near it he would be ensnared.

But there was nowhere he could run, no place in the multiverse he could flee beyond Loki's reach. Loki had the mantra—oh, christ, that _was_ how. That was _why._ He'd told himself it was irrational paranoia, but it had been true all along: Loki had taken it from Steve. He'd taken the override from Steve, and now when Tony finally knew where Loki was he couldn't do a damn thing, because everything he'd prepared to throw at Loki was _useless_ without extremis. Even with it—all Loki had to do was _start_ the mantra, and Tony would drop, screaming, forever, and nothing he had would be quick enough—

He could call the armour to him with the Space Gem but it would do nothing, it was too late. He could call Steve into the Gap, where Loki wouldn’t follow—but that would destroy Steve, too: Steve still had his soul. And if Tony took him anywhere else—

The image of green eyes staring out of Steve’s face made him want to retch.

_What the fuck am I doing, I can’t leave him—_

SHIELD would only realize too late. Tony appearing with the failsafe having activated—they’d take too long to realize, they’d _pause_ , and that would be all the time Loki would need. He'd move Steve like a puppet. If he wanted to. He didn't need to. There was nothing Tony could do to stop him from doing whatever he damn well wanted.

 _I can’t fight him._ Loki was all around his sense of the armour through the Space Gem—all around his sense of Steve. _I can’t do this_. He was poised on the brink of mindlessness and Loki hadn't even started in on the mantra yet. _I can't._

A thought bubbled up from somewhere deep in his brain, and if it hadn't been so desperate it would almost have sounded like Steve: _Find someone who can._

He ripped a hole through time and space and dropped himself, naked and crouching over the inert blobs of his armour, into Reed Richard’s lab. A second thought picked Steve up and yanked him there as well.

“Quarantine him!” Tony shouted, pointing at Steve, who was standing there empty-handed, looking so goddamned _confused_. But the shout was unnecessary; blue light cut down around them both less than a second after they’d appeared.

“ _Unauthorized intruders detected,”_ said a pleasant and obviously robotic voice over an intercom, and Richards snaked his head out from behind a bay of computers.

“Oh, my—um,” said Richards.

Steve staggered, and collapsed first to one knee, then to the ground. He lay there, motionless—Tony couldn’t tell if he was still breathing.

One of Richards’ hands stretched across the roof to hit a button on the wall, while the rest of him rushed around to stand in front of Steve’s force-field cage. _“Medical assistance required in Dr. Richards’ lab,”_ announced the intercom.

“Tony, what happened?” Reed asked, flicking a hologram into existence—one that displayed two sets of vital signs. _Oh, thank god._

Tony felt himself sink to his knees. His breath seemed far too loud; he couldn’t make it any quieter. Steve was—well, he’d gotten Steve away, at least. In everything else he had failed, but—if anyone could figure it out, Reed Richards, other-reality super-genius, could figure out how to get Loki out of Steve’s head, or could at least protect him in the future. _Please._ Steve would be—would be—

His own pulse thundered in his ears. In his head someone was screaming, but no sound made it past his throat. No air.

“—just appeared—”

Steve knew, and Loki had gotten into his head and turned him inside out. Loki knew, and Tony had just defied him.

He'd always known it would come to this.

“—not answering... shock?...”

Tony let his eyes slip shut, and waited to start screaming.

 


	16. Mind and Matter: 4.1

** PART 4: MIND AND MATTER **

_Cause and effect reversed, and out of a hundred thousand fragments the Time Gem condensed into a single, solid stone, clenched tight in Tony's fist._

_It was done. The universe remained a little bit darker, and exactly as dark as it always had been. The changes travelled both forward and backward, rippling off of the other changes that he had made, reflecting and refracting as he reverted to forward-time._

_He hit the loop again, and this time he saw everything in forwards-motion, saw all the failures, the deaths. Tripitaka spoke words of pain to smash him into the ground—words he couldn't feel from this lofty vantage; words that weren't directed now at him—and he never learned. The toll rose, each iteration adding new failures—_

No.

_This wasn't like before. He began to look again, methodical even in the face of so many of his own fuck-ups, and that was when his brain caught fire._

nononononoSTOPAWAYAWAY

_All his muscles were seizing; the headband left him enough for full consciousness but not enough to move. He flailed, but every movement registered as damage, and he tried to rip his scalp off and claw away the headband beneath, but he didn't know if he managed to move his arms. He screamed at the Gems, words failing and thought coming only as concepts, the need to flee, backed by inhuman agony and bitter betrayal._

_The responses from the Gems he could feel—they were sharp and quick to respond, the knowledge dizzying as a kaleidoscope, an alternate way of looking at the universe while the headband kept him anchored to physical space and time._ Forward _, he went, but the mantra didn't cease, and the marrow of his bones felt like it was igniting, consuming, and he couldn't think, and he begged_ AWAY _but he couldn't get away and it wouldn't stop. He fell through a sky of ash and then a sky of green and then a sky of coral, worlds in quick succession as he fled and it followed him, a merciless constant. He was screaming and he couldn't hear himself think and the sky went black and there were no stars, because he had failed in Maklu and Steve had failed him and Steve had_ lied _and everything was going to die, he had seen the end before and it would come again and he was losing his mind, extremis slipping out of control, the armour shredding off of him like razors clawing through his skin._

Something hooked into the Time Gem and _pulled_.

His forward momentum cut off; his view of the universe, already handicapped by the mantra, broke completely as everything warped, reality trying to impose itself over the Gap—blue sky and blasted rubble, none of which was really here. _He_ wasn't really _there,_ but something _wanted_ him to be. A wave of information slammed through the Time Gem and into his brain, a cosmic upset that shattered nerves and stars alike. The Time Gem burned like fire against his palm, damage relays ticking up as it pulled at him, and some part of him was aware that unlike the mantra's false effects, this—whatever it was—was actually killing him.

He couldn't tell if the headband was still punishing him. Pain had been overtaken by vertigo, and if he'd had a stomach he'd have lost his lunch, but the Space Gem was dead in his hand and the Time Gem was turning him into existential taffy. The Space Gem was in his hand, in the Void, and it was also at the centre of the multiverse, not ripping him apart but stretching him to infinitesimal thinness as it inexorably pulled at the Time Gem, and him along with it.

There was no air in the Void, so he couldn't scream. His lungs had been reduced to mere concepts, anyway. With the last of his fading consciousness, Tony dug in metaphorical heels and yanked backward, pulling away from that merciless grip with everything he had. Data crashed as Time and Space jumped to obey frightened, incoherent thoughts, everything NOISE and timestammmmp 0xAAAA sit.dove.. 0x''1B33'. loc

Something massive slammed into him, swatting him like a fly. His perception of the flipsides of Time and Space cut off. Errors cleared, and suddenly he had enough presence of mind to realize that what had hit him had been the ground, and he'd dropped the Gems. Damage indicators were shrieking at him, but the mantra had stopped and they were nothing compared to it, easily ignored while he struggled to move, or failing that, write code to assist repair functions. His muscles were locked up from pain and the impact, he couldn't breathe, and the low-oxygen indicators were giving him a headache.

Before he managed to get his wind back the headband constricted again, once more drowning him in agony.

 

* * *

 

The world around Steve was glass-blue and still. Unnatural. He struggled to sit up, but it was as if his body was not quite connected to the rest of him. Nothing resisted him, but nothing moved, either. Alarms started to ring in the back of his head, and he tried harder, to no avail. He couldn’t feel himself breathing. Had he broken his neck? But he couldn’t even feel his face, couldn’t open his eyes.

He pushed against the glass, and it wouldn’t budge. He tried to yell, but no sound emerged.

_Am I dead?_

Fighting to move didn’t do anything, but it also didn’t tire him out, so he kept fighting. It was impossible to tell for how long. And then—

“All right,” said a voice. Elderly, male, educated—a voice that had been groomed very precisely. “Time to wake up, Captain Rogers.”

Steve opened his eyes and found himself staring at a light blue ceiling. His chest rose, filling with air, and he felt that, felt the coolness of the air, heard the hum of electronics around him: a medical bay. There was a man in a wheelchair sitting beside his bed, holding a gem that glowed blue from within, and Steve was out of the bed and pressed up against an invisible wall before he’d thought to move. His shield—where the hell was his shield? He couldn’t see it anywhere.

“Easy,” said the man. “I’m not your enemy, Captain. Far from it.”

“There’s no way you can prove it, you’ve got _that_ ,” said Steve, pressing further back against the force-field despite himself. Stupid, _stupid_ —he should have lunged forward, tried to grab the gem away. If that had been his reflex, then he might have been able to take it through surprise, body moving before the mind caught up.

“Unfortunately, that is true,” the man conceded. He opened a small metal box that had been sitting in his lap, and popped the gem inside, shutting it firmly. “A reaction that is entirely valid, but which I hope you will overcome in time. My name is Charles Xavier. I’m a friend of Dr. Reed Richards—of Earth 3490.10, as you would know it. I’m also a natural telepath. Reed asked me here to see if I could determine the extent of the damage that Loki had done to your mind, and, if possible, repair it—which I have done. I’m afraid I needed to use our mind gem to be certain, as it was by the Mind Gem that the damage was inflicted. You’ve been unconscious for a little over five hours.”

“How am I supposed to believe this,” said Steve. He couldn’t quite manage to make it a question. Behind him, the force-field shivered, humming with energy.

Someone with a mind gem wouldn’t need a force field.

He looked at Xavier. “You’re reading my thoughts right now.”

“No,” Xavier said gently. “I believe in personal privacy.”

Steve looked around. This place—it looked familiar. It was almost the identical to the medbay he’d woken up in before, when he’d first gone time-travelling and Anthony had brought him to Reed Richards to save his life. Of course, it _would_ be familiar, if it was all in his head. _Damn it_. He didn’t even know when he’d gone down. He had been with Tony and Fury, talking about the Reality Gem, and they’d gone to Maklu, and then—the memories were wrong. They had to be. He could recall the images and sounds. He could even recall his thoughts: he could recall thinking he should incapacitate Tony, and when that was done, call Loki.

They made no sense, and beyond that, they _felt_ wrong, like a loose tooth after a fight. Were they real?

“Captain, I know you have no reason to believe me, or to believe that this is real.” Xavier waved a hand at their surroundings. “That is an entirely natural reaction to someone who has been through what you have. If you wish, later, I can... dull it, for you, make it easier to believe—but I would not do so without your consent.”

“I can’t know that.” Loki. What the hell did Loki have to do with any of this? 3490, Steve remembered—other worlds, and negotiations, and finding Tony and getting him back from the Mandarin. Before he and Jane had wound up in 3490, they’d been with Loki, looking for the Power Gem... but, damn it, those memories were wrong, too. He felt no doubt at all about that, unlike the more recent ones regarding Loki.

“You can’t,” Xavier agreed. “When it comes down to it, none of us can know—are we real? When we reach out to touch another person, is that real? We think, therefore we are... but our senses are the only gateway we have to the world. That is as true for a telepath as for anyone else. Captain, I understand what you are feeling.” Xavier leaned forward, hands on the armrests of his wheelchair, and—he looked so damn sincere. Steve swallowed. “I do. Ultimately, you are left in the same position you were in before this experience. You can choose to act as if what you perceive is real, or you can act as if it is not.”

“It doesn’t matter what I see if you’re directing what I think.”

“I am not, but I understand your doubt. You have the tools, however, to process that doubt and make your own decisions despite that natural uncertainty. The human mind is influenced by its entire environment, and is experienced at dealing with such pressure. Consider, Captain Rogers, that people who will never meet a telepath in their lives are influenced every day—and resist influence every day—from everything they see and hear: confirming their own biases and opinions, challenging them, or causing them to abstain from judgment. In time, reality will prove itself to you again.”

“The last thing I can remember is fake.” He tried to shut his mouth on that as soon as he said, berating himself for having such loose lips. He shouldn’t have admitted to it.

“The last thing you remember, before waking up here, was influenced by Loki. He did you several disfavours when he used the Mind Gem upon you. First, he destroyed several of your natural memories, which I’m afraid are gone beyond my ability to recover, even with our own gem’s aid. Second, he placed a sequence of false memories in your mind. I can remove them, if you like. For now, I’ve simply flagged them as false, so that you can clearly tell what they are and decide yourself whether you wish to be rid of them. Third, he placed a compulsion upon you, one he buried very deeply. It would not have been visible even to me without our mind gem. I have managed to clear the compulsion, and also flagged the memories of what you were forced to do while caught in its influence. Those memories are, unfortunately, quite real, but your actions in them are _not_ your fault.”

Steve’s legs felt wobbly, and he put out a hand to steady himself. He had... was he really considering believing anything that Xavier was saying? The guy had a mind gem. But those memories in his mind—they were fake, he _knew_ that the ones of Loki and trying to find the Power Gem were fake. The later ones, the ones that seemed ‘weird’ and not just _wrong_ —but they were wrong. Lord, he’d stripped Tony of extremis, called Loki to them both, and just _handed_ the Reality Gem over to him.

Oh, God. If Loki had been in his head, then he would know the key-phrase for the Makluan headband.

“What he pulled from my head...” Steve had to take a breath before continuing. “Do you know what it was?”

“Yes,” said Xavier. His eyes were far too kind, far too full of sympathy. “He is not terribly skilled, and his work left... marks behind, although I have done my best to heal them. I’m afraid he dug deeply into your secrets.”

“Oh, God.” Steve swallowed. “Tony. Did he—” He remembered, with that same sense of it being _off_ , that Tony had disappeared. Tony had disappeared, Steve had handed Loki the Reality Gem, and then the next thing he knew, the world flipped inside out and he’d been... in Dr. Richard’s lab? It had been the one that they’d been testing the infinity gems in, not this medbay. Force-fields had slapped down around them, and Tony had been yelling something—it had sounded like Tony—but he couldn’t remember what Tony had said. All his senses had been overwhelmed by pure _rage_.

At how Tony had betrayed him, he’d thought at the time.

“Mr. Stark is...” Xavier hesitated, and Steve felt his stomach seize up. “Loki has done nothing to him. However, he is not well—he collapsed shortly after managing to transport you here. He has trapped himself in his own mind. I am confident I can pull him out of it, _without_ the gem’s aid, but doing so would require, in some small part, changing his mind. Whereas in your case I was simply repairing artificial damage, and removing an external influence, in his case my involvement would need to be more active.” Xavier met Steve’s eyes calmly. “It is not something I will do without medical consent.”

“I’m his medical proxy.”

“I know.”

Steve had to take another breath. He breathed out through his nose, slowly. _Assess and evaluate._ Xavier had a mind gem; it could be that none of this was real, or that his decisions were being influenced. But, whether it was because his reasoning was affected or not, the only reason Steve could see _not_ to play along was defiance. Meanwhile, if it _was_ real, and only him in his head now, then not playing along might leave Tony trapped in some sort of catatonic state.

“I want to see him,” said Steve, stepping away from the force-field.

Xavier nodded, and a moment passed—then the force-field around the medical bed vanished. “Of course. He’s in the next room over.” He pressed a small toggle on his chair, wheeling it around and toward the door.

“Where’s my shield?”

“Also with Tony,” said Xavier.

After that, there was nothing to do except follow him. The bright blue-white tones of the medlab and the hallway outside made Steve want to flinch away. They were too close to the colour of the gem... or was he just seeing them that way? There was no damn way to be sure. But he followed Xavier into the next room, more of a lab than a medbay itself, where Reed Richards, Sue Storm, and Toni Stark were waiting for them. They all looked expectant: they must have gotten notice from a monitor that Steve and Xavier were coming. Steve lifted his chin as he was met with three assessing gazes at once—and then he looked past them, his attention captured by what Reed, Sue, and Toni were standing around.

Tony was laid out on the table. It wasn’t a medbay bed; it looked more like a lab bench, although it had been covered with a sheet, and Tony was staring up at the ceiling with half-open eyes, chest bare. Steve remembered the armour falling off of him, when he’d been stripped of extremis... when Steve had stripped extremis from him. Someone had covered Tony with a blanket up to the waist, but he still looked uncomfortable and cold, lying so still.

Steve’s shield was propped neatly against one of the table-legs. He strode forward and scooped it up in one hand, keeping his eyes fixed on Tony. As soon as he felt the metal of the shield, with its unique balance, he knew it was his—but Tony... Steve laid a hand on his bare shoulder and squeezed gently. Tony’s skin felt cool, dry. There was no sign that he registered Steve’s presence, not even the slightest hitch in his slow, shallow breathing. His left hand was clenched tightly into a fist, so tight his knuckles were white. Steve reached for his hand, and nearly startled back when his own fingers slid _through_ Tony’s, emerging from the other side of Tony’s fist curiously elongated. For a moment he wondered— _Mindscape?—_ but, no: there was a faint sheet of purple light where their hands _should_ have touched. The Space Gem... creating a _wormhole_ through Tony’s hand? The sight was both curious and nauseating. Steve resisted the urge to shudder as he took his hand back.

“So,” said Toni brightly, drawing all eyes to her as if she’d been at the centre of a colourful explosion—until she spoke, Steve hadn’t realized how much the room felt like a deathwatch. “He gave you override codes for extremis, hey?”

Steve glanced at Xavier, who brought his wheelchair up to the bedside. Tableside.

“No, Charles didn’t tell,” said Toni, following his glance. “I took a peek at his firewalls—and, hell, Steve’s got an override for me.” She crossed her arms, her armour gleaming beneath the bright lab lights as she moved. “ _But_ —this is important—he can still think without extremis online. He managed to shout a warning that you were compromised, when you both showed up here. I actually don’t think extremis has anything to do with this, although I think getting it back online wouldn’t hurt.”

“It could also complicate things immensely,” said Xavier. “Extremis expands the mind in a way not otherwise seen in humans, and Anthony is already trapped within a mental loop. Extremis may shock him out of it, or it may bind him there more deeply. It would be safer for me to draw his mind out first.”

“It’s a gamble,” Toni agreed. “Without you reversing the code”—she spoke once more to Steve, now—“I don’t think I can re-enable it anyway, or at least, not today. Give me a few days... it’s a foreign set-up, what he’s got going on.” She shook her head. “I think I like mine better.”

“Yours has its drawbacks, too, Toni,” Reed’s voice floated over from behind a bank of computers.

Steve fought the urge to cross his own arms. If he did that, he’d either have to shift and put the shield on his back, or he’d be moving to hold the shield directly in front of him. Either way was unacceptable: he _needed_ the shield right in his hand, but he couldn’t come across as hostile to these people. Not with the mind gem right there.

He looked at Sue Storm. “What’s the third option?”

Toni’s expression flickered. Disappointment? Doubt? If it was directed at them, or inward... Steve noted it carefully, but kept his eyes front and centre, fixed on Sue.

“The third option is to send you both home in the state you’re currently in,” said Sue, studying him in turn. She flicked her gaze to Toni, then back. “That’s your right, of course. It may be that your own people can come up with some other way to help him.”

Maybe. Steve had had his mind rifled through by _Loki,_ and neither SHIELD's medical techs nor their quacky psychics had picked up on it. SHIELD was going to need to change every code and password that he knew of. He was compromised. He couldn’t shade the truth, here, like he suspected that Natasha and Tony had about their experience with Gaea: the security risks were too high. Fury would probably bench him—and, hell, it would be the right call under other circumstances, except that everyone knew damn well that Steve was the only one who could stop Tony, and Tony was still considered volatile. Now it had been _proven_ that Steve could.

If only Tony hadn’t given him the override code—

With sudden cold clarity, Steve realized that if Tony hadn't, then Steve would have taken him down with the Makluan mantra. _Thank God that it didn’t happen._

But what had happened was bad enough. If they asked Earth-3490 to send them home, would SHIELD even _want_ to try and help Tony, now that Loki had leverage over him? Keeping Steve benched indefinitely would give them the perfect excuse not to try.

Besides all that, there was no one back on their Earth who understood extremis well enough to help Tony with it, except for Maya Hansen and Tem Borjigin, who were both completely out of the question. They certainly didn’t have their own mind gem.

Make that _almost_ certainly. There was nothing that he could be absolutely sure of right now. But he needed to make a decision.

“That’s not the best option,” Steve said, and Sue nodded.

“We didn’t think so, from what we’re seen of your world.” She paused. “We haven’t contacted it yet. Jan and Hank—excuse me, I mean Dr. Hank Pym, Jan’s husband—did go over a few hours ago, as part of the science exchange, but apparently your absence has not been explained to her. _My_ main concern—well, that can wait, I think, until we decide what to do about Anthony here.”

Steve nodded. Her main concern was probably the Reality Gem. He could remember its power, easily felt just from holding it... and he could remember handing it over to Loki. Even the smile on Loki’s face hadn’t fazed him, at the time.

He looked between the three of them—four, really, but most of Reed’s body was still hidden behind computer banks. “What do you think is the best way to wake him up?”

Both Sue and Toni looked to Xavier. Well, he was, according to him, a telepath, even beyond the powers that the mind gem granted him. Maybe it a was lingering suggestion, or maybe it was sheer common sense that such a powerful man wouldn’t claim to be a telepath if he wasn’t, but Steve believed him. “Dr. Xavier?”

“So much is unknown about Anthony’s version of extremis that I am afraid I am out of my depth where it is concerned.” Xavier spread his hands, palm up. “Without reactivating it, my course would be to suppress the impetus behind the thought-loop that he is caught it—a modification to dampen that particular combination of emotions and trapping logic. It would need to be permanent, I’m afraid. Removing my influence afterwards would leave him constantly on the brink of falling back into that trap.”

“And if extremis was re-activated?”

“Then he might come out of it on his own. Our expert in _terrestrial_ extremis informs me”—he nodded to Toni—“that extremis coming online is similar to a computer being told to restart; many errors can be interrupted simply by turning the machine in question off and on again. But I have no idea how likely this is to be true in this case, and, of course, Anthony’s version of extremis differs significantly from Toni’s. The worst case would be a total collapse of his mind inward, although even then I’m confident that I could retrieve it. At that point, however, my intervention would need to be far more intrusive.”

They didn’t know. No certainties. Steve rubbed his thumb along the edge of his shield as he thought. Going back home without fixing this first was a bad idea. Would any other world have a better idea of what Tony’s extremis would do to him? _Probably not, damn it._ Tony’s version was built off of Makluan nanites from Maklu itself, and none of the worlds they’d contacted so far had ever visited Maklu. Trying to find a world that had could take forever. And even if they did... Earth-3490, at least, Steve knew. If they went elsewhere, they’d be dragging Tony’s secrets all over.

Xavier already knew the secret that Steve had failed to keep from Loki. The one thing that had frightened Tony the most... and Loki had taken it from Steve. The very least that Steve owed him was to avoid giving it to another telepath or technopath.

And he also owed it to him to choose the least intrusive option possible.

“The first one, then,” said Steve. “Wake him up before re-enabling extremis.”

“Very well,” said Xavier, and he wheeled his chair around Steve so that he was sitting near Tony’s head. The box containing the mind gem was still sitting in his lap, but he didn’t reach for it. Instead, he just stared at Tony, his head slightly tilted and his gaze far away, as if contemplating something that they all couldn’t see.

“Probably for the best,” Toni concluded after a moment. But there was something terse about the way she said it.

“This will take him a few minutes,” Sue murmured, stepping around and holding out a hand to nudge Steve over to a counter closer to the wall, where a coffee machine sat with a half-full pot beneath it. Steve let himself be herded, but put the counter slightly to his side and back, so that he could keep an eye on Tony while Sue grabbed mugs out of a cabinet and poured coffee into two. Steve juggled his awkwardly when she handed it to him. He wanted to keep both hands on his shield, grounding, and wound up carrying the mug in one hand, with it pressed against the edge of the shield. If he pressed too hard, the mug would shatter, and it was just shy of painfully hot against the palm of his hand. He ignored it.

“Mine too, please,” said Toni, wandering over after a half minute with a mug of her own. Steve could see a circle of coffee residue at the bottom of it when she handed it over to Sue, who filled it obligingly.

“We do need to talk about the Reality Gem,” said Sue, her voice lowered like she was in a hospital sick-ward. It was an accurate enough comparison. “Charles didn’t tell us anything else he read in your thoughts, but he did tell us what happened with Loki. Loki has the Prime Reality Gem now, and we’re lucky that he doesn’t have the Prime Space Gem, too.”

Steve had to look down at his coffee at that. Loki had the mantra. If Tony kept hold of the Space Gem, then Loki could take it from him any time he so chose.

“Loki’s shown pretty definitively that whatever his intentions towards the multiverse cluster as a whole, he’s no friend of Earth,” said Toni. “Any Earth, but especially yours. We need to decentralize. We can’t run as much as we have been through your Earth. For one thing, your SHIELD has way too much control and is way too damn totalitarian—sorry to be blunt, Steve, but you have to see it.”

“I do,” Steve said to his coffee. He forced himself to take a sip of it and raise his eyes. “I'm surprised you consider inter-reality cooperation a priority.”

They both winced. “Historically, opening portals to other realities hasn't gone well,” said Toni. “And the way you guys keep concealing information from us sure doesn't _help_ here and now, but... we need to put aside our differences. This is too big.”

Sue looked sympathetic, but he could tell she was in total agreement with Toni. Toni... it was _strange_ , seeing Toni, with a similar expression of sympathetic-but-firm on her face. She was younger than Tony actually was, even if she looked to be a well-aged decade older, but the knowing in her eyes belied that. She might have been born years later than Tony, but she’d started on the life of a superhero a decade before he had; she’d known her version of Steve for so much longer. There was understanding in her expression that wasn’t present in Sue’s—Toni _knew_ him, knew him and had known him, and he didn’t know how much he knew about her at all.

“Hey,” she said after a moment, when Steve didn’t say anything. “Look. One crisis at a time, okay? Two max. We’ve seen worlds plenty worse off. Your SHIELD is dangerous, but it’s not completely strangling. You’ll get there. It’s a work in progress. Journey, not destination.”

“I guess,” said Steve after a moment. He _was_ aware of the reality. Things changed, people changed, generally for the better, but there was no such thing as perfection—only the constant struggle towards a better world. And yet... this was also a war, here. Once the current crisis was over... he had to wonder, then, if he’d still be around to keep fighting that fight on his home ground.

Or if Tony would be around.

Or when Loki would bring down the axe.

From across the room, he heard a hitch in Tony’s breathing. The coffee became less than unimportant. He set it down and strode back over, reaching the table just in time to see Tony blink—properly blink—and bring a hand up in an unconscious defensive move: palm outward.

“You’re safe,” said Steve, which was a lie worthy of Loki.

“Where—” Tony cut himself off. His eyes went briefly distant, again, and Steve stiffened, but Tony blinked again and the distance was gone. He sat up, slowly, curling up one knee to counterbalance himself. The light of the Space Gem, shining through his fingers, began to fade.

His expression as he looked at Steve was scrupulously neutral. Blank.

“I’m sorry,” said Steve. He swallowed. There was more he ought to say—

“I returned Steven to himself, and freed him of Loki’s influence,” said Xavier, and Tony’s face went slack with relief. Then he tensed again, glancing over at Xavier, who continued gently, “You recall what I explained to you just now?”

Xavier hadn’t said a single thing aloud to Tony that Steve had heard. That was probably for the best; it was undoubtedly private. And if it had to do with the Makluan headband... then it was doubly best that it wasn’t said aloud, where other ears might hear it.

“Yeah,” said Tony. He didn’t elaborate.

“Then you understand why I must ask you to surrender the Gem that you hold.” Xavier nodded to Tony’s left hand, still clenched in a fist about the Space Gem.

“Um,” said Toni from behind Steve. Steve stepped to one side to make room for her, belatedly realizing that he’d been blocking her and Sue’s approach. “Not that I consider it unwise on general principles, but, Charles, what?”

“Loki possesses a great deal of leverage against you,” said Xavier, still focused on Tony, but clearly speaking for the benefit of the rest of them. “I am not suggesting that I be its keeper. Choose whom you wish. But choose someone else.”

Steve tried to catch Tony’s gaze. His expression was blank, staring downward as he unfolded his fist to reveal the Space Gem sitting in the palm of his hand. “You’re not wrong,” Tony said quietly, and held the Gem out to Toni.

Toni stared at him. “Hey, look—I mean, your Steve is right _there—_ ”

“But he’s not from your world,” said Tony. “He wouldn’t be the best choice considering what you want to do with it.”

“What do you—oh,” said Steve, realizing in the next moment what Tony meant, as he considered what _he_ would have done with it.

Of course. Despite how Steve had lost the Reality Gem—had _given it away—_ Tony had proved that it was possible to use the Space Gem with a reflected gem to retrieve the Prime version. This world had not one but all of their reflected gems; they might be able to retrieve the whole lot of them, or at least the ones that Loki didn’t already have. Privately, Steve doubted whether it would make a difference if he tried or somebody from 3490 did. He hadn’t had any particular problems using the soul gem given to him by an alternate Earth’s Stephen Strange. But...

 _Better to let somebody from here try._ They’d already handed all their secrets over to these people, and they hadn’t been betrayed yet. Besides... he couldn’t blame Tony for not trusting him. Not when he looked at Tony’s blank expression and knew exactly why it was there, and that it was all his fault.

And Loki’s fault.

But Steve had been so damn sure he’d managed to keep Loki out of his head, so damn arrogant about his ability to defend against mental attack. _You idiot, Rogers._ The first time that he’d manage to repel Loki from his thoughts—that had been real. Xavier hadn’t flagged that memory as false, at least. But had Loki just been faking? He must have had the Mind Gem all along, after all.

_Damn it!_

“Take it,” Tony told Toni, not dropping his hand. “You’re the only one I can easily give Maklu’s coordinates to.”

“Fine,” said Toni. There was a telepath sitting right beside him—but she reached out and took the Space Gem anyway. Maybe she’d followed Steve’s line of thinking.

“Be careful. It’s easy to get overwhelmed. And Loki’ll have good reason to keep an eye on Maklu.”

“I’ll be careful as hell,” said Toni, tucking the Gem away. “We know that Loki has the Mind Gem and the Reality Gem. That leaves Time, Power, and Soul.”

“Time was free. But...”

“Please don’t tell me you lost that one, too.” Toni stared at Tony, and he looked away. “Oh, for god’s sake!”

“We’ll go after Time first, then,” said Sue, cutting Toni off. “Of the individual Gems, it's the biggest long-term threat. Charles, Reed, will you come with us?”

Reed’s head leaned around to rest on Sue’s shoulder; it made his neck into a very disconcerting rope. “I’d like to, but you know I have other items I _must_ oversee here. Sue...”

“We’ll be careful,” she promised him, and pecked him on the cheek.

“I will come,” said Xavier, after a polite cough. “It may be inadvisable to attempt to take the Mind Gem from Loki directly, but I believe we should take its reflection along—in which case I am the obvious candidate to use it. We may find it grants some protection.”

“Or not,” muttered Tony.

“It’s worth a shot. You’re right about Loki, he’s bound to be staking the place out. We could use some experienced guides, too,” said Toni, looking between him and Steve. She shrugged at the look Tony shot her. “No, it would be stupid to give you the weapons of ultimate doom if Loki’s got leverage on you. But you’re the only ones who have been to Maklu before, and—sorry, Steve—Tony, you’re the only one with proper _readings_ on it.”

“I could give you logs.”

“The full sensor sweeps?” Toni snorted. “I doubt that.” Her eyes flashed, and there was something that was left unsaid on the end of that, some technopathic communication with Tony. Tony rolled his eyes in response.

“I don’t think it would hurt to have us along,” said Steve. He couldn’t help but add the qualifier—but if there was a way he could help, here...

 _You ought to be going back to report in._ That’s _your duty._

No. His duty was to save lives—to find a way to stop what had happened to Earth-294010 from happening to any others. If he could help Toni and the others find the rest of the Prime Gems, then he’d be doing so. He’d report in, and take his well-earned punishment, when he’d fulfilled that objective.

“So,” said Toni, almost challengingly. “You’ve got your armour.”

“No, I don’t.”

“Cancel override 54,” said Steve, and from beneath the table, what Steve had taken to be a steel block—a container of some sort—melted into a silver stream that flowed up onto the table and onto Tony’s skin. Tony blinked, looking surprised.

“Then we just need our time gem,” said Toni. She made a face. “On the other hand, this means we need to go bug Namor to cough it up, again. Christ, yesterday was bad enough—”

“I could make him,” suggested Sue. The set of her expression suggested she might enjoy forcing the issue with this ‘Namor’, whoever that was.

“You could also use it as a test,” said Reed, from his position still on Sue’s shoulder. His hands, Steve noted, were still tapping away at the computer he was using on the opposite side of the room—apparently, he didn’t need to see the screen to keep working. “You have the Prime Space Gem, and you know where Namor is keeping the time gem from this reality. You should be able to retrieve it.”

“He could have moved it.”

“If he wasn’t too arrogant to think his defences sufficient,” said Sue. “If he has, try looking elsewhere in Atlantis. It’ll be there somewhere.”

“It’s not that straightforward,” said Tony. His eyes were fixed on the Gem—no, Steve realized, he was watching the light-shadows cast by the Gem, moving on the far wall.

“Then it will still be a good test.”

Toni pointed at Sue. “If he comes here all irate that I’ve stolen it from him, _you_ get to deal with him.”

“I look forward to it.” And _that_ , Steve thought, was a really damn ominous smile.

“Here goes, then,” said Toni, and the Gem flared in her hand, purple light filling the room.

Something not quite like wind, not quite like pressure, rolled outward past the walls of the room—“Going first, searching later,” said Tony. He had to be viewing this through some other sense than the ones that Steve possessed... or maybe it was just more experience. “If you know where it is then you know where to look—if you have too many then—there you go.”

“The peanut gallery was unnecessary, thanks,” said Toni tartly, and she opened her other hand, palm up. There was a flash of orange light and what had to be the time gem was there, floating above her hand for one long, drawn-out second before it dropped into her palm.

Tony gave her a stiff little half-bow, which looked ridiculous considering he was still sitting cross-legged on the table, only half-wearing the armour—the rest of his extremis was wrapped around him like a foil heat-blanket. “Just trying to be useful.”

“Be useful and suit up,” ordered Sue. She stepped back to give Reed another peck on the cheek, and for a moment a nearly-invisible bubble surrounded them both. Steve saw her lips move, but no sound made it to his ear, and he averted his eyes. Toni held out her hand, and her helmet—previously sitting by the coffee-maker—zoomed into her outstretched grip; she pulled it on. Xavier opened his box and took out the mind gem, setting the box on the table that Tony had been sitting on as Tony climbed down, his armour forming fully around him. Panels flickered across it. For a moment, he vanished from view, and then was visible again. A more thorough systems check than normal, Steve realized, even as he found himself going through the same kind of motions, checking his shield’s straps where they were affixed to the vibranium.

Sue and Reed’s bubble vanished, and Reed withdrew a few feet to give them all a look-over. “No unnecessary heroics,” he told them, mouth set in a serious line. “This isn’t that sort of mission.”

“ _We’ll be good,”_ promised Toni. _“Man-me, coord—thanks. Alright. In three, two, one—”_

She’d been holding the Space Gem for all of a few minutes; Tony had had it for days. The difference in experience and familiarity was immediately obvious— _hang on. Was Tony using it when nobody else was looking, these past few—?_

The thought tore away from Steve, as his stomach attempted to do so as well. A riot of colours whirled past, dancing about nauseatingly. His limbs were leagues apart, then compressed together; he could feel his body stretching out impossibly, distances folding in on themselves and inverting. Space twisted, around and around and around— _I’m going to be sick_ , he realized, and at the same time, horribly, knew that if he was he might _actually_ puke up his insides.

Then they were there.

Everybody staggered, except for Xavier, who listed badly to one side in his wheelchair instead. “Good Lord.”

“ _No backseat drivers,”_ Toni declared, but even through the armour she sounded unsteady.

“ _Recover quickly,”_ said Tony, though he himself was doubled over, hands on knees. Toni flapped a hand at him, which was an odd sight with them both in near-identical armour. But she held her hands held out, the Space Gem’s purple light beginning to glow... and Tony froze, halfway through the process of straightening. _“I don’t—”_ His armour locked into place, eerily statue-like. Lifeless.

“Tony?” Steve asked.

“Ah,” said Xavier, and he raised one hand, holding the mind gem. It was burning a bright, bright blue. “Loki.”

As he said the name, it became possible to see the god standing there, not even ten feet away, and holding the Mind Gem—the Prime one—in his own hands.

“Charles Xavier,” drawled Loki. “Such an honour, to meet one of the finest minds in the Nine Realms.”

“The honour is mine,” said Xavier politely.

“So I just said.”

Xavier was unruffled. “Please let go of Anthony.”

 _Divide his attention_ , Steve thought. Was it his own thought? He couldn’t tell, but he stepped forward anyway, past Toni, who was standing very still, her hands balled into fists. So long as she had to be careful about holding the two gems, she wouldn’t be able to use her main repulsors. They needed to give her a chance to finish. Beside her, Sue had her hands up and there was light bent around her palms, power just waiting to be released.

“I don’t think I will,” drawled Loki. His eyes tracked Steve’s movement. “Hello, puppet.”

“Got my strings cut, now,” said Steve, rather than grinding his teeth. _Hurry up, Toni._ “How’s breaking free of fate working out for you?”

Loki laughed, a loud, belly-shaking laugh, and his lips curled back in a grin too wide for his face. Insanity glittered in his eyes, a mix of merriment and despair. “Working out? Oh, it’s worked. It is work. A work in progress, you might say... you see it, don’t you? Darling?” There was desperation, there, as he stared at—Toni—

“Out of her head, godling,” Xavier ordered, his own voice thick with strain.

Loki snarled at him, and the comm in Steve’s ear crackled to life—Tony’s voice, frantic, _“Nonono, don’t look there!”_ Tony moved, beginning to turn, and then froze again with the motion incomplete.

Loki lunged forward like he’d stolen all of Tony’s momentum, a knife suddenly in one hand, the blade a foot long and glittering, serrated silver. The reflections off of the uneven metal showed nothing that was around them, not the blasted wasteland, not _them_ , but instead something with too many sides, too many angles to fit into reality—Steve tore his eyes away as the air in front of Loki shimmered like a heatwave, and Loki was tossed head-over-heels. He came up in a crouch and threw the knife underhand.

Steve lunged to interpose himself and the shield, and the next thing he knew he was flying sideways—Sue had her right hand flung out to the side, and she grunted in pain as the knife sunk deep into her left shoulder. He’d gotten tangled up in her attempt to deflect the knife, but the knife must have gone straight through whatever she’d been trying to do. Steve hit the ground, rolled, came up on his feet, and threw the shield at a sharp angle. He charged at Loki as it bounced off of a wide piece of debris, ricocheted into another piece, and bounced back to strike Loki in the back of the head just as Steve kicked up to crush his windpipe—and his shield whistled harmlessly over his boot. He barely caught it before it would have smacked him in the head instead.

It had been an illusion, whether of light or of the mind, Steve didn’t know. He turned as he recovered from the kick, scanning wildly, but Loki was nowhere to be seen. The knife in Sue’s shoulder was gone, and blood spurted from the wound in time with her heartbeat, surging past the hand she tried to clamp over it. She needed help ASAP—Steve ran towards her as she fell to her knees. It must have hit an artery. He clamped his hands over the entry and exit wounds, one on either side, but couldn’t manage to get a seal; her flesh around the wounds was like porridge. That damn _knife_ —

“ _I—oh, god—”_ said Toni. Her hands were rising slowly, like she was trying to shield her face. Orange and purple light burned bright—as did blue, from Xavier’s hands.

Xavier held the reflected mind gem high, his eyes narrowed. “Ah. There you are.”

“ _No.”_ It was as much a thought as a sound. The bright point of light in Xavier’s hand went out—the gem was gone. For a moment, there was a look of deep shock on his face—“Here I am,” finished Loki, appearing right behind the wheelchair. He raised the dagger high, and Steve threw his shield as hard as he could—Sue collapsed as he let her go to do so—

The dagger struck home first, burying deep in the back of Xavier’s neck. He went over, hard, folded over on himself by the force of the blow. A second later the shield caught Loki in the chest and whipped away.

“ _OH GOD, NO!”_ screamed Toni, the sounds breaking apart in the armour’s vocal filters, and Tony finished his lunge, grabbing at her hands. She ducked away, and he caught only the right. Sparks flared as the two armours competed, and both came off the worse—the purple light fell as the grip of Toni’s right gauntlet loosened, the armour at her wrist fracturing beneath Tony's grip. She shrieked, and her left gauntlet closed with a horrible _crack_ of breaking stone. It was more than sound; it felt like a punch to the gut.

“Y-”

“ _Ge-”_

Steve’s shield, bouncing back, slammed into him and began to knock him over; it was moving faster than anything else. Loki’s scream of rage turned into a bass note. Tony’s hand dropped after the falling Space Gem—too fast, faster than light, and yet still too slow to outrun the bronze and tangerine fire breaking from Toni’s left hand.

“-ou-”

“ _-t-”_

Shocks ran up Steve’s fingers, vibrations from the shield as it transmuted energy and diffused it. He didn’t have his balance. Gravity was acting very slowly, but his reactions were slower still.

“-f-“

“ _-ba-”_

Above Toni’s hand, at the point where the time gem had shattered, the air was solidifying into black obsidian—light itself was trapped, moving too slowly to escape.

“-ool-”

“ _-ck-”_

Tony’s fingertips touched the point of purple light that was the Space Gem, and the world vanished. The universe roared past: universes, and multiverses, pinpoints of light and entire realities all tangled up together. Steve was the only thing standing still.

Gravity reasserted itself, along with reality, and Steve’s perception switched back: he was the one tumbling head over heels, thrown by a great deal more force than his shield had hit him with. The ground rushed up to meet him and he turned it into a roll, bleeding momentum—but not enough to stop before he smacked right up against a tree trunk. The cost of a dazed moment was too much: he lurched to his feet before he knew what had happened, spinning about to face the threat.

But there was no more threat. The world had changed, from broken glass to alien forest, and everyone else except Tony and Toni were gone. Toni was screaming, a high, metallic shriek that shook the air, and Tony was still grappling with her—she twisted her hands around and blasted him square in the faceplate, sending him flying into the trunk of the nearest, enormous tree. Bark splintered and he bounced to the ground, leaving an Iron Man-shaped dent in the massive trunk. The purple light of the Space Gem was buried in a pile of pine needles and went out.

Toni’s helmet fell away in pieces to the forest floor and she kept screaming, clutching at her head with gauntleted fingers, staring skyward with eyes full of mindless horror—

“ _Don’t!”_ shouted Tony, but too late. The repulsors flared again.

Silence fell.

Slowly, like one of the majestic trees around them, Toni’s body toppled to the earth. The heavy weight of the armour she was wearing hit hard enough to scatter pine needles. The smell of char filled the air.

The light dimmed, and Steve realized he was blinking. Burned flesh and bone, vapourized brain matter—yes, it smelled exactly the same. He’d done this before. A headless body lying on the forest floor; a headless body lying between server racks. A repulsor node on the hand of a corpse. A dead friend. Suicide. His fault.

In the aftermath of violence, the forest was as silent as Tony's workshop had been.

Steve leaned over and threw up.

Bile burned his throat like betrayal— _why would you—_ and guilt _oh god I let you—_ until there was no more to come up. He spat several times and wiped his face, then stumbled backwards, until he hit the rough bark of one of the massive trees, and slid down it to crouch at its trunk. Freshly-fallen pine needles breaking beneath his boots added a sour, citrusy smell to the air, one alien to Tony’s workshop—Steve grabbed blindly for a handful and crushed them in his fist, trying to ground himself. He spat to the side again, and wiped at his face. Then he stood and kicked more over the mess he’d made, but it didn’t do anything to hide the acrid smell.

Steve stared at the body—her body. Bodies seemed oddly disproportionate, without the head there to make them look like... people. The thought felt almost blasphemous in its irreverence. Actually, the whole thing felt fake. Unreal. Birds had started twittering again. High overhead, the sky was blue. Was this just a mindscape? Steve put out a hand, and managed to find the tree-trunk behind him again. Having it as a support didn’t make him feel any less like his feet were floating.

“ _We fucked up,”_ said Tony, the metallic tones of the armour hollow and dull.

It felt like there was something he should do—close her eyes, _something_ , but—she’d done a thorough job of blowing her head off. What was he supposed to do? He felt like he’d vomited up all the adrenaline from the fight; his legs felt shaky and useless. Loki—if this wasn’t a mindscape, Loki might have lost them.

He tried walking forward, vaguely in Tony’s direction, and fell to his knees halfway there.

“ _I’m sorry,”_ whispered Tony.

A bird trilled. After a moment, another joined in.

Behind him, Toni’s headless body felt like a weight. And it—was. He was responsible for Tony... he’d lost the Reality Gem. He’d agreed to Tony handing over the Space Gem, to this whole idea... they never should have returned to Maklu.

“We need—” Steve tried, and then had to stop and cough. His throat hurt. The taste in his mouth was utterly foul. He could smell nothing but blood—Sue’s, all over him: his hands, his uniform was drenched in it. He tried again. “We need to go back.”

Tony had propped himself up against his tree, huddled over. Now, his helmet turned slowly towards Steve, and although the faceplate remained as expressionless as ever—the thought struck Steve that it was by choice, now that Tony had extremis—he nonetheless managed to convey an air of disbelief even before he spoke. _“To_ him? _Fuck that.”_

“Not to Maklu.” Steve shook his head, as much to give himself time to think as anything else. “Home. We need to go—report—”

“ _Fuck that,”_ said Tony. His voice was dull again.

“We have to,” Steve insisted. He clenched his hands into fists. They didn’t feel so shaky, now. Arguing with Tony was good for _something_ —“At the very least we need to—to bring her back—”

“ _It’s a corpse. She’s a fucking corpse, she fucking blew her own head off—”_ Tony hauled himself up to his own feet, and Steve stood to match him without even realizing it, striding forward, shoulders back as Tony got up into his face and Steve glared right back. _“It’s a fucking corpse, it doesn’t fucking matter!”_

Steve didn’t raise his voice back. The sick feeling in his gut burned like white fire, a tiny, condensed star of rage. “Pick up the goddamn Gem and take us back.”

“ _Or_ what?” breathed Tony. His helmet melted away, and beneath it his eyes were dark and wild, terrified. “You’ll make me?”

They stared at each other, eyes locked, hurt and furious.

Tony broke first, turning away, his shoulders slumping downward. He took a step back, then another; when he spoke again, it wasn’t towards Steve, but instead towards one of the massive redwoods. “I don’t know how to get back. I have no idea where we are.”

“What?”

“Loki has the Mind Gem,” Tony said, and there was no helmet to make his voice sound that dull, but it was. “If I’d thought of a destination he’d have been able to follow, so I just—thought, screw it, _go_.”

Steve buried his face in his hands. His breath was harsh in his ears—he could feel his shoulders shaking. _Pull it together_. “Tony, it’s the Space Gem. God Almighty, you can cross the entire universe with that thing. There has to be a way you can use it to get back.”

“Me?” Tony smirked at him, an ugly rictus of a smile. “Pick it up? _Order_ me to, then—”

“For God’s sake, Tony, I—even when Loki mind-controlled me, I didn’t!”

“...No. No, you didn’t.” Tony’s grin twisted further downward, and he looked away.

“I don’t know how to use the Gem,” said Steve, struggling to keep his voice under control. He needed to not shout, and to not let his voice crack. _Calm. Even._ Tony was shaking, so he had to be calm. “Tony. If Loki uses the mantra, can’t you use the Gem to get away—”

“It doesn’t work like that.” Tony fidgeted, clenched his hands into fists and relaxed them again. “I tried, okay, I developed a whole new method of interplanetary travel because I thought if I could portal far enough, then I could get away, but it doesn’t work like that. Working on the portals doesn’t even give me a migraine, because the sound doesn’t matter, not really, it’s all frequency—the immediate change at a distance is... well, tachyons, why am I trying to explain this, it doesn’t fucking _matter_.”

“Tony—”

“It doesn’t even give me a headache telling you this, I’m that fucked. It knows I’ve fucking given up. I tried and I failed, okay? There’s _nothing_ left to try.”

Tony was right: Steve _didn't_ understand how Tony could be convinced it wasn't even worth trying, except that he'd despaired and given up without trying it, because Steve sure as hell hadn't helped him with any experiments.

Then he looked again, and saw the bleak, helpless loathing behind the despair. He thought it was mostly self-hatred. But there was a flicker of something else there, dark and certain, that stopped Steve in his tracks.

“He's used it on you.”

Tony didn't nod. But he look on his face was answer enough.

“Jesus, Tony. When?”

For a few seconds, Tony didn't say anything. Then, quietly: “I dropped the Time Gem.”

That had been _weeks_ ago. “And you didn't _tell_ me? If he stole the Time Gem then—everything we just did—!”

Steve gestured backward, one arm flung out to indicate the headless body lying on the ground behind him. Lord, they'd left the Space Gem with Tony, and all this while, he'd known for _certain_ that Loki had the mantra, and that the override code wouldn't be enough against it—

_And who gave Loki the mantra, weeks ago?_

But why hadn't Tony _told him?_ If he'd known for _sure_ that Loki had the mantra, right after Steve had come back, maybe he'd have told SHIELD's psychics to look deeper. Maybe they'd have _found_ something, before Steve had handed over the Reality Gem and everything had gone straight to hell.

_And then SHIELD would know._

But for all he'd promised Tony he wouldn't tell SHIELD, keeping back something like this was going too far. They'd lost the Reality Gem. Toni was dead. Sue and Xavier were dead. If Tony had just _trusted_ him—

Steve turned back, a frustrated snarl rising in his throat, and caught sight of Tony's face. He was as pale as a sheet, watching Steve much like a rabbit might eye a hawk. There were bags beneath his eyes, and a new hollowness to his cheeks, new lines of strain creasing his artificially young skin. When had those appeared?

It occurred to Steve that for all that Tony had answered the question, he still hadn't technically told Steve about it. He hadn't talked about it at all except in the most circuitous fashion.

_Maybe he can't._

Deliberately, Steve took a breath and tried to make his voice calmer. “I'm sorry. I didn't—” his throat closed up around his protest. Of course he hadn't meant to tell Loki, but Tony didn't need Steve trying to assuage his own guilt right now. “I'm sorry, but I have to know. Did Loki take the Time Gem?”

Tony dropped his gaze, then shook his head. Some of the frantic mania was gone. “I don't know. I dropped it. I thought it was somewhere... in a reality. I wasn't in the Gap. But Toni... when she went looking for it, she looked right into the Gap. Christ, you know what’s there, and she looked in there with the _Space Gem_. She’d see the whole thing at once. I didn’t realize what she was doing—it’s not even there, it _can't_ be there,” said Tony. He ran his hands through his hair, bouncing on his feet with nervous, frightened energy. “I checked afterwards, remember, and it’s not there. The minor gem shouldn’t have pointed her there—” He looked up, eyes wide. “Unless somebody moved it back.”

 _Shit._ “Tony, I need you to get us back home.”

Tony clenched his hands back into fists. “Promise you’ll stop me.”

“I—what?”

“Loki’s got—it, he grins at me I’ll break. You can stop that,” said Tony. His face was bloodless. “You have to. Promise.”

“I will,” promised Steve. “I will. I already promised, remember? You gave me the code—”

“That’s not enough. That wouldn’t _stop_ me, it’d just slow me down. It won't even work if I'm not there to hear it—”

“I'm not going to _torture you,_ Tony.”

“You want me to pick up the Gem again?” Tony asked, his voice thin and brittle. “That's my condition. Equal threat makes a no win scenario, and anyway, if my mind’s gone I probably won’t be able to—”

Steve became aware that he was staring at him with a different kind of horror. “I promised you I wouldn’t—I won’t—”

“I’m _asking_ you to,” said Tony, desperately. He was shaking. “ _You_ hate the idea of it, how the fuck do you think _I_ feel about it? Yes, fine, I'm a coward and I didn't tell you, but I'm telling you now, this is the only fucking way. He had the Mind Gem and I was right there in front of him. Every plan I had, it’s not going to work because he _knows_ , now! There’s nothing I can do against him! If it comes to it, you _have to_. Both sides using the trigger will make it useless—”

“No,” refused Steve, and again, “No—” but with each syllable that left his lips, the desperation on Tony’s face grew.

 _Not just the pain,_ some part of Steve realized dimly. _He’s terrified of the failure._

_Of failing... me. Earth. Everyone._

_I’ve failed him already._

“Alright,” said Steve. He swallowed. Everything felt numb; the words, like heavy leaden blocks. Like nails in a coffin. “I—okay. If it comes to it—if there’s _no other way_ —if he uses it on you. I’ll—stop you. I’ll use the damn mantra and stop you.”

“Okay,” said Tony. His breath was coming in quick, shallow increments—hyperventilation, Steve recognized dimly. After a moment, Tony buried his face in his hands, and Steve stepped forward, horror rising—but no light flared; there was no terrible, lethal blast. Steve took another step forward, wrapped his arms around Tony, armour and all, and hung on.

They stood like that until they both stopped shaking. Tony had turned one gauntlet away from his face, clinging to Steve’s shoulder in return. At last, he sighed—an empty sigh, one without weight or life: an exhalation—and stepped back. Steve reluctantly let him go.

“We need to go back,” Steve said, when he made no further movement and the silence threatened to drag. Back to 3490... back to their own Earth. Back to SHIELD, and the Council that would barely let them lift a finger in defence of another Earth.

But the call not to help 294010 had been Fury’s, and Fury couldn’t be accused of apathy. Consideration, caution... Fury hadn’t just gotten three people killed trying to make another run at Maklu, either.

Tony glanced aside. “And then what? We do the dutiful thing”—his eyes strayed in the direction of Toni’s corpse—“but then _what?_ Christ, we’re coming back with a corpse. We’ll be lucky if we don’t start an interplanetary war on top of everything else.”

“We’ll figure it out when we get there.”

“Fury’ll bench you.”

“Maybe,” Steve acknowledged. Under ordinary circumstances Fury’d be right to, but they were in crisis-mode, these days. “We need somebody to use the Space Gem. Even if Loki—even with Loki, that should probably be you, if there’s risk of spreading your mind across the Void while using it. Clint, or—well, probably Clint—will take lead of the Avengers—”

“No, he won’t,” said Tony. “You need to be there to stop me.”

“So maybe Fury won’t bench me. We’ll figure it out.”

“Fuck, Steve, when the Council hears you, if Fury doesn’t bench you—if he doesn’t throw you in fucking _jail_ —they’ll fucking fire him. 3490’s going to want our heads on pikes—”

“Forget the Council. Listen to me—Tony. We have allies in SHIELD. We have friends, we have people we can depend on. 3490 isn’t going to go to war with _us_ over this. We have to trust the people we have as allies—Fury can handle the Council, we can handle whatever the other Earths throw at us. If we have to run then we will, but Tony, give them a _chance._ ”

He couldn’t trust Fury to defend other Earths, but he _had_ to trust that the man would defend his own. They had to go back. They should have gone back the first time.

Fresh from the horror of what Loki had done to him, he had wanted to do anything but, and look where that had gotten them.

“Well,” said Tony. He swallowed. “I have to, right?”

Steve closed his eyes and reined himself in. “Tony. I swear to God—I promise, if Loki tries to use that mantra to make you bend, I’ll use it to stop you. But there is no other way in Earth or heaven that I will ever use it against you.”

“Unless he catches you with the Mind Gem again,” Tony pointed out quietly.

“The Gems are complementary, right? The Space Gem has unlimited range—the Mind Gem doesn’t. I’ll stick by you, you can teleport us away.”

_Until Loki uses the mantra himself..._

Tony swallowed, and didn’t say anything. He didn’t move towards where the Space Gem had fallen, either.

Steve squashed a sigh, and made himself keep his voice level. Calm. “Tony. We can either go back, or we can stick around here. We have a war to fight. I am not sitting it out.” If Tony wanted to, then Steve wouldn’t blame him. But his own position was not an opinion: it was fact. He _could not_ let it pass him by—if Fury tried to bench him... well, he’d be right to try.

But Steve knew he wouldn’t stay benched.

“Okay,” said Tony quietly. He held out one hand, palm out, but looser than he usually did for repulsoring things—and the Space Gem appeared in front of it, floating until he grabbed it.

Steve stared. “How—did you know you could do that?” He hadn’t been able to before, surely; he’d had to grab it directly from—from Toni.

Tony shrugged differently. “Stuck nanites to it. I can find it, now.” The armour loosened, extremis flowing upward to form his helmet. _“Should’ve done it earlier. To the Time Gem, too.”_

He stepped around Steve, and, reluctantly, Steve turned, until Toni’s body was once more in his line of view. He wished, well, he wished a lot of things. Tony raised one hand, and Toni’s body rose—was that extremis, or the Space Gem? Then a shroud appeared to cover her from head to foot—from _head,_ because the shroud wrapped around the gaping, empty space where her head should have been.

“Is that real?” Steve couldn’t keep himself from asking.

“ _No. Illusion,”_ said Tony, one hand coming up to tap the centre of his chest, right over the reactor and the ICG. _“I thought—”_

“Yeah,” said Steve quietly. “Thanks.”

“ _Not for you,”_ said Tony, but it wasn’t hostile. He lowered his hands. The Space Gem was nowhere to be seen. Subspaced? Dropped into the Void? Did it matter, so long as Tony could still use it?

“ _Okay,”_ said Tony. His faceplate was looking down, away from Steve; he sounded like he was talking more to himself, but surely, between extremis and the armour, he wouldn’t be speaking aloud unless he meant to. _“We’ll take her home.”_

When reality dissolved around Steve again, it almost felt familiar.


	17. Mind and Matter: 4.2

_It’s not a point._

The underlying fabric of reality wasn’t really all that complicated, Tony thought, as he tried to orient himself against the pattern of the universe. _Reduce, reduce, reduce..._ One unit became all natural numbers, became integers, became fractions, became the full set of rational numbers.

 _Which are dense enough to give a picture, if not the details. Too damn dense._ Right now the Space Gem floated in the void, a monolayer of extremis nanites wrapped around it—and because it was a point there and also a point here, _with him_ , his mind was in both places, too, standing beneath redwood trees carrying a corpse and staring out into the Gap. _Vulnerable at two points instead of one._

Viewed that way, neither looked like a point anymore.

_If I carry it for long enough, will I figure out how to see the real number set?_

Looking out into the Gap through the Gem didn’t require sampling. There was so little _reality_ in the Gap that he could look at all of it at once. There was less reality actually _in_ the Gap than there were barriers _between_ reality and the Gap, barriers that made up the understructure of existence, keeping out the Void. Or was that right? It was pretty, anyway, like looking at Earth from high orbit—distant, tiny continent-stars below, and the Space Gem spread itself and his mind out along those un-distances. Almost idly, he looked for traces of the Time Gem between them—but there was nothing. If it had been there when Toni had looked, it was now gone.

Tony turned his attention back to the more immediate problem, the solution that Steve had asked for. Like the observable universe, there was a structure to the cluster, branches and nodes of multiverses grouped closer together than others. _One. Two. Three..._ He oriented, and knew where home was. From the wide view he zoomed in—and in and in and in—

A became B. They didn't move; the Space Gem didn’t work like that. Rather, the pattern shifted.

Tony opened his eyes and let the power of the Space Gem fade away—not entirely, not enough to let go of it—but enough that the awful pattern beneath everything went out, and when he blinked everything made sense through eyes designed by extremis, through extremis designed by a mind that existed in reality and not across it.

_Note to self: don’t do that for too long._

Force-fields slammed down around them: the blue shielding of the Baxter Building’s security systems. Tony reached out to disable them, hesitated, saw that a field had shimmered into view between him and Steve, and grabbed for them again—only to slide off of the strongest firewalls he’d ever encountered.

 _“Unauthorized teleportation detected,”_ said the Building’s pleasant tenor. _“Unauthorized connection to security protocol alpha denied. Initiating security measures—”_

“Override,” said Reed Richards, stretching up from his chair, and, “Good lord, what happened? Or, should I ask first, which Earth are you from?”

“Dr. Richards,” Steve said, his voice going raspy. Tony shot him a look without moving; his face was set, but determined. Or at least, that was how it would have looked if he hadn’t been covered in blood; as it was he looked like a nightmare. “I—I’m so sorry.”

“Hmm,” said Reed, tapping a communicator in his ear—surprisingly enough, with his hands; _shouldn’t he be able to deform his ear enough to do that?_ “Sue, would you mind coming up to my lab? I’ve got some unexpected visitors. Um, Building, we need some decontamination here.”

_Sue_

_What the hell?_ Almost by reflex, Tony grabbed for the security cameras, and the rebuff this time came with a bit of minor malware—enough to give him a headache. _“Unauthorized connection to security system denied. Warning: further attempts to access this system will be met with countermeasures.”_

“Iron Man, please stop that,” said Reed, slightly pained. “At least I’m assuming that’s you? I can’t just grant you access to the Building without even knowing which universe you’re from, you must understand.”

A pair of robotic arms folded down from the ceiling, shooting out a blue light at Steve—Tony scrambled for control of them and was met with a friendly acknowledgement from the Building’s cleaning service instead of another headache. Beneath the gentle blue beam, the blood caking Steve’s gloved and suit-front began to disintegrate.

Steve shut his eyes. After a moment, he said tightly, “This is the wrong reality.”

Tony let himself sink into the resonance of the Space Gem... just a bit... more... _“No, it’s the right one. It has to be.”_ If it wasn’t—

The automatic door hissed open again, and this time Sue stepped in. “Well,” she said, taken aback as she saw their cargo, and automatically further on guard. She stepped carefully around the force-fields, assessing. “We were expecting versions of you, but not this soon. And not with a corpse.”

Not this soon.

Tony twisted, staring down at the illusory shroud covering the other armour. Bits of tachyon radiation still clung about the corpse’s hand. A time gem had broken. But the shockwave that had hit them had been a dilation field—if anything, their own times should have moved further ahead without them. It shouldn’t have travelled in reverse—Maklu kept course with all things, even if not pace—

_Oh, really? What the hell do you actually know about time gems, Stark?_

The Space Gem was not a point.

The Time Gem was not—

The forcefields were neatly cutting off his connection to—well, anything. But he was outside of them, too. Or he could be. He sank deeper into his awareness of the Space Gem, and reality—

_Reality —_

Outside, and surfacing—

Local time: 19:30:05 

_“We haven’t returned yet,”_ Tony blurted.

After spending an hour and a half testing the Space Gem's resonance with 2490's reflected gems, they'd left 3490... only twenty-six minutes ago local time. They'd returned to their Earth, and then stupidly, foolishly taken their reality gem to Maklu—did Loki have the Prime version, then?

 _Yes,_ the timestamps on his memories provided the answer a moment later. Local time was four minutes before they were due to show up on this world, Steve brainwashed—still brainwashed, that was; he’d been brainwashed before they’d gone to Maklu—and himself about to become half-catatonic. Five hours before they’d gone to Maklu a third time, this time with guests, and fucked everything up beyond belief all over again—

Which brought him back to the question of where _were_ their past selves—the light of the Space Gem flooded his brain, and it wasn’t light, it wasn’t photons or waves or energy at a point in space, it was a metaphor as much as a physical thing. The Space Gem existed here. It existed in the Void. It existed in Maklu, twice over—and then that was too much, two Gems too close together, and his awareness dissolved into chaos, watching one universal pillar break causality and another shift to accommodate it.

His thoughts hiccupped. Tony blinked, and found that he was looking up at the ceiling. From his... location on the floor.

Local time: 19:30:19 

“Tony!”

He cleared the helmet away. “I’m—fine.” He was fine. He was lying on the floor, still. He—this body—hadn’t gone anywhere. But something was wrong, he felt like something had just been knocked loose from his head.

_I just witnessed metaphysical annihilation, I’m great_

The thought of going back and looking again made him shudder.

A hand appeared in his field of view—his eyes’ field of view, that was. The force-fields were gone, although Sue, with her ability to recreate them on demand, was 1.6 metres away, ready to raise a few manually if she had to. Tony reached up and clasped Steve’s hand in his own, and let Steve haul him to his feet. Toni’s corpse—not-her-corpse—remained sprawled on the ground beside him. Beneath the still-functioning illusion, it was no longer a neat bundle, instead lying with its limbs splayed out haphazardly. He’d dropped it when he’d greyed out, there. _I’m sorry..._

“Also, I think Loki just killed us,” he said. The giddiness was a bit slow to fade. “Or I might’ve. Uh. Something with that many fireworks probably had a physical effect.”

“I’m taking it that the—or a—Time Gem was involved here,” said Reed, moving over to stand by his wife. It wasn’t really clear why Tony briefly passing out was cause to suddenly trust them, but apparently they did; no need to pin them in the middle of the lab, then.

Understanding dawned on Steve’s face, and then urgency. “Can we stop—”

“No. Too late for that.”

“For what, exactly?” asked Sue.

Her husband’s brain went in a different direction, apparently, because he started to say, “Actually, overwriting events with a time gem is perfectly possible, even if it’s—”

“I know how it works, Reed,” Tony cut him off—maybe too harshly. “I just saw—it doesn’t matter. This can’t be changed with a reflected gem.” He’d felt the power in that backlash. It was a hell of a lot. It was _familiar._ He’d been able to outrun it with the Space Gem...

 _She was looking into the Gap._ Toni shouldn’t have been able to find the Time Gem there, not the Prime one—but what if she _had?_ When _he_ had found it, he’d had to rewind to the point of shattering and then... _No, that was the Window shattering. The Gem was already in the Window, it was already partly broken._

He thought about it, running simulations—probability functions going both backwards and forwards in _t_ , worked into _ω_ with differing laws than causal analysis would allow...

_The Time Gem can break causality. I just saw that! We're seeing that right now!_

But just because it _could_ didn’t mean it _did—_ partly, or entirely. The Window had been made of broken bits of Time Gem, but the Gem hadn’t yet shattered when the Window still existed—that had happened afterward, when he’d paradoxically reformed it out of its shattered pieces. Kuan-yin had told him the Window had formed at the beginning of time, and they didn’t know why— _But what if we just saw it happen?_ Made of the broken bits of a Time Gem configured into a different form, or maybe it was different because it had in part still been a different _gem_ , a lesser one that was never meant to try to stretch across realities...

He couldn’t trust this sort of hunch; the mathematics for this shouldn’t have been intuitive. But, damn it, he _knew_ he was right. _How_ did he know? Some half-remembered blip of information from when he’d held it himself? The Time Gem had broken, forming a break in the fabric of Reality, and the Window formed around it... like a scab, to prevent unreality and reality meeting... like they shouldn’t have, like a line shouldn’t be both unique and not, like he shouldn’t be able to flip into the Gap with his portal device in order to move between worlds...

No. He needed math, he needed logic—logic that was breaking down. Was that the Time Gem? Breaking reality, _causality_ , and therefore logic?

“Tony,” said Steve’s voice, jostling him from his thoughts. He looked up and found that they were all looking at him.

“Sorry. I—what’d I miss?”

“We need to know about this,” said Sue, “and about whatever happened that still exists. It’s obviously big.” Her expression was brisk, no-nonsense—but not unsympathetic as she added, tilting her chin toward Toni’s body, “And we need to know what happened here. _Is_ it a body? I can tell you’ve got an illusion up—”

Tony dropped the illusion—then pulled it back up, too fast for the human eye to register. _That was crude._ “It’s a body,” he said, and then... couldn’t think of what else to say. _We fucked up. ...Yeah, that’s not crude..._

_They’re scientists, not just her friends — they’ll understand_.

He dropped the illusion, slowly, now more than glad that he’d capped off the headless stump with extremis nanites—nanites he was never, ever going to touch again. At least it was some kind of dignity. At the time he’d done it just to stop the awful burned stench—he could turn off his sense of smell, but Steve couldn’t. Steve had taken it worse.

Steve was still taking it worse; he made a soft, pained noise beside him, too quiet for anyone unenhanced to hear. Tony glanced at him and saw that he had his head bowed.

Reed and Sue stared. After a moment of shock, their expressions became more neutral, evaluating. “Building,” said Sue, “call Toni Stark.”

 _“Calling,”_ said the Building, and then Toni’s voice came on, asking, _“Sue?”_

The relief that crossed Sue’s face was brief, but heartfelt. She’d already processed that it _hadn’t_ happened, Tony thought, but hearing a friend— _Huh. I guess they are friends._ Friends he might have had, in another life, if she and Reed had existed... and he’d had boobs... or, maybe without the boobs.

 _Probably wouldn’t have married Steve without the boobs._ Which was a weird thought on many levels.

He pulled himself back from that tangent and called up the debugger program, which had sat inactive since Gaea’s cure. He shouldn’t still be this giddy. Should he? He needed his brain to _work_ if he was going to start tackling the mathematics of the Time and Space Gems.

“Our 199999 guests returned,” said Sue. The designation seemed like a phone number—like a _jingle_ — _Well, that’s horrific. 199-999 for all your world-destroying —_

He cut himself off.

“They had an adventure with a time gem. And you, apparently.”

“ _Do I have a clone now, and is this a problem or the sort of situation that gets fixed with a time loop?”_

“You’ve dealt with time loops before?” Steve asked quietly.

The Building’s phone protocols picked him up anyway; it was Toni who replied. _“A few times. Never good.”_

“Well, in this case they brought you back in a body-bag,” said Sue. “So, no time-loops, please.”

“That sounds highly unlikely from what Anthony has said,” Reed remarked. He’d stretched himself out again, so that looking at him was like looking at an Escher. _I could do that. Kinda. With the Space Gem, if I wanted to..._ Tactically, it might be worth exploring. It wasn’t such a leap to make, either: even now, via the Space Gem, he was back on Earth-199999... not quite home. SHIELD’s lair wasn’t ‘home’. _Poor little orphan boy billionaire, no real home —_

Except he wasn’t a billionaire any longer. The Tower was dark. The Malibu house was covered in police tape. Pepper was living in a hotel on emergency funds, and drinking her way through the mini-bar fast enough to need to order in more. JARVIS was gone, dead, or deactivated: the single solitary back-up of him that Tony had been able to find, he hadn’t been willing to activate. So long as JARVIS was in stasis, at least he was safe. As safe as any of them were.

Back ‘home’, his mind tapped into the security systems—SHIELD could stand to learn a lot from Reed. From what Tony had seen of the guy, most people could, except that he was so far beyond them that they... couldn’t. _It’s lonely at the top._ Back ‘home’, Bruce and Jane were exchanging theories rapid-fire with a blue furry guy and a costumed superheroine. They looked to be enjoying themselves; but if they brought Jane into contact with one of the Prime Infinity Gems, would she call Loki, too? Natasha and Clint were reported as off-world. Pepper was still in her hotel suite: a bottle of scotch was sitting, open, beside her.

These thoughts flashed through his head and were seen, acknowledged, and processed by the time Toni replied, not missing a beat, _“Got it. Is the temporal imbalance resolved or are we going to be dealing with chronal slips, here?”_

Everyone else turned to look at him for that answer. There wasn’t enough _data_ for a proper answer. The Space Gem checked all the data there was. “Resolved? The multiverse is already breaking down on a fundamental level—have you seen that proof?”

_“Of course I’ve seen it. Fair point, man-me.”_

“We need to debrief,” Steve cut in. “Back home.” His eyebrows pinched together. “And probably you guys, too, but—we need to let them know what happened. And... she deserves a funeral.”

He was carefully avoiding looking at the body itself, Tony noticed.

“It didn’t happen,” Reed observed, but his arms stretched out to wrap around the ungainly form, cradling it like something precious.

“It did.”

_Enough of it did._

Steve was at least right about needing to tell Fury _something_. Passwords were easily changed, access was easily fixed, but everything else that Steve had seen and Loki must have pulled out of his head— _No. Don’t think about it._

But he had to think about it sometime. Loki had been _there_ —in Maklu, in the Prime Reality, in person... and Tony hadn’t had extremis; he’d missed his shot. A second shot and he’d had extremis, but without the Space Gem, and Loki had been _in his head_ and knew every way Tony had thought of to kill him. The brief chance at a third shot hadn’t even had a chance to get off the ground, before the Gems clashed and reality rewrote. It was too much to hope that Loki had gotten caught in that catastrophe.

And Loki knew everything he’d planned, now...

He’d failed. Used up all his chances. Three tries—with the Space Gem, even—and he’d missed every goddamn one, and there was no way Loki would give him another. He could figure out the mathematics of the Time Gem all he wanted and it wouldn’t matter one fucking bit, because he’d had it in his hand and then he’d _lost the damn thing._

“Tony?” said Sue, looking at him in concern. “Are you okay?”

 _“I’m fine,”_ said Toni, over the speakerphone.

He closed his eyes. The Space Gem couldn’t let him run from this. It couldn’t even settle the nausea in his gut—he could turn that off, with extremis. But why bother? No point. “We fucked up.”

“You did,” said Reed, and it sounded harsh, but it wasn’t. “But now you have another chance.”

_No, we don’t. I don’t._

“Reed, can you get some robots...?” asked Sue softly, nodding at the body. “Storage for now—we can have a service later.”

 _“Please, uh, don’t mention this to Steve,”_ said Toni, her tone light. But there was something underneath it, anyway... Reed turned away, carrying the body to the door of the lab; there was a whirr, and in the hall outside, mechanical arms spooled out of the walls. Reed handed over his burden, and Tony watched without eyes as the arms passed her along down the hallway and towards an empty lab—one with a refrigeration unit—each movement gentle and respectful.

He wished he could have introduced JARVIS to this Building.

“It can be discussed later,” said Sue. “Here’s what’s going to happen. You two need to go back to your Earth, and debrief, and get medical attention. I’m going to come with you. Your SHIELD doesn’t have a good record with sharing information that needs to be shared. And, if something happens, I’ll be there to provide backup. Reed—check with Namor. We need to know if our time gem is still here.”

Yeah, she hadn’t missed a thing. Steve looked like he wanted to protest; extremis’ logs provided crystal clear details about Sue Storm disintegrating.

But the thought of needing protection against SHIELD was laughable. It had a collection of threatening individuals under its influence, and the thought of them learning his secrets terrified him, but as it was, if he just _left_ , there was nothing SHIELD itself could do to him. He might have considered them a threat—via Steve—to what he needed to do, but... he’d fucked that up all on his own.

When it had come down to it, in the heat of the moment, he hadn’t even tried to take a shot at Loki. He’d just run away.

 

* * *

 

The headband let him go again after what felt like hours. It was more probably just minutes, but it could have been hours. It could have been seconds, or years. His internal clocks were all out of whack, disagreeing violently with each other, and he didn't have an external signal to reference. Even if he'd been back on Earth, he'd flung himself god knows how far with the Time Gem, rendering external references useless.

Damage warnings still screamed at him; pain raced up and down along nerves enhanced with nanites, leaving him shuddering and twitching. Oxygen reserves were low. Oxygen reserves were very low. Atmospheric oxygen: 14.2; oxygen recapture initiated 

Auto-repair routines fixed critical systems first. He lay there and let them. Another time he might have written code on the fly, boosting the automatic systems and providing overrides for his autonomic nervous system to prevent further abuse of sore and twitching muscles, but right now his brain felt more abused than all the rest of him combined. He hadn't felt this bad since—since—

Since Tripitaka had smashed him into the ground beside the Window-Font-Whatever of Time, nine-tenths dead and the last tenth only because the headband was designed to punish without killing.

And now someone else had the mantra. Or Steve had used it. Tony closed his eyes and focused on taking gulps of air, catching his breath. If any of it sounded like a sob—he couldn't bring himself to care. All his worst fears were confirmed: even the Time and Space Gems together weren't enough to save him from it. He couldn't stop shaking. The anticipation strung him out like razor wire: whoever had it had used it twice already in short order, would probably be using it again, soon.

The traitorous thought occurred to him, then, and he found himself scrabbling in the ashy dust of the alien planet he'd landed on. For a moment his eyes wouldn't focus, and panic strangled his lungs, but then his fingers found the Gems. He picked them up, and the thought wouldn't stop.

Steve had the mantra. Loki had taken Steve. Either Steve had betrayed him— _oh god please_ no—or Loki had ripped it from Steve's thoughts...

_i'm so fucking screwed i'm so fucking screwed i'm so fucking screwed_

Tony knew what Loki wanted: the Time Gem. Giving it up might be enough to save himself.

Laughter bubbled up from his throat and he let it, choked on it, and wound up curled up on his side and coughing for breath again, tears leaking from his eyes. Oh, god. Christ. Sure. He could hand the Time Gem over to Loki—and Loki was Loki, was just as likely to reward him with another fucking round of it—

Or maybe it wasn't Loki. Maybe it was someone else! He laughed again, hysterical and shrill because if he wasn't laughing he'd start screaming again. Maybe he'd hand over the Gems, the pair of them, and Loki would pat him on the head and send him on his way, and maybe when Thanos ate the universe there'd be no one to say the mantra and he would finally, _finally_ be free of it.

Tony laughed until he couldn't breathe and had to pause to gulp down air. The headband didn't ignite again. His muscles stayed clenched, tendons taut, braced against it—never mind that it wouldn't do anything. The thought of coding away that reflex was exhausting.

He should just hand over the Gem. Both Gems. It was probably Loki.

Even if it wasn't, Loki no doubt had some trap set up for when he returned. Loki had Steve, after all; even if this _hadn't_ been him, what were the odds Loki wouldn't get it out of Steve?

He didn't know. He didn't want to think about that equation. There was nothing he _wanted_ to do except simply stop existing, but even with the Time and Space Gems pressed against his fingers it didn't happen.

But.

There _was_ the active option.

Even with the headband and the afterlives he'd seen, there was... one hope remaining to him. One weapon that he'd designed as a last resort, before reality had crept in and it had slowly dawned that taking Loki with him was almost certainly the best he could hope for. Back when he'd thought he was his own clone, he'd thought the price to be worth it; when he'd learned he wasn't, he knew it still would be.

But it had always been a wild hope, and now it was even less than that: Loki, in all probability, had the mantra on his side, and had amply proven that the Time Gem was no defence against it. Even his precious last resort would take too long to use as a _weapon_. Even with the Time Gem: the mantra had proven that however it worked, it couldn't by stymied by distance in Time or Space. Slowing time to try to gain an edge would do nothing except, likely prolong it, and that was—Tony shuddered, and his brain shied away from that. He couldn't. He _couldn't_ do that, could barely contemplate it.

There was no weapon he had that would work against Loki, not now. And he'd never had a prayer of coming up with anything that would work against Thanos. It was like he'd told Bruce: they weren't high enough on the Kardashev Scale. The Gems weren't enough. Even the fucking Elder Gods weren't enough, and he'd been an idiot to allow himself a few hours of hope.

He'd lost most of his extremis nanites, but he hadn't lost his subspace inducers. It only took a few seconds' thought to pull out what he was looking for—although that was just the trigger mechanism. The bulk of the weapon was layered through different dimensions in a way that was imperceptible to human senses.

There wasn't much grace to it; it looked like an overenthusiastic tape measure. The beauty of it was all in the mechanism: it was the ultimate anti-everything, and there was nothing it could not completely, totally obliterate. He'd taken the name from its counterpart in another world, although he'd had to work out how to put it together on his own. Nobody in that other reality had been stupid enough to leave directions lying about.

Anybody living in _this_ reality would probably be pretty pissed at him if he triggered it here. For the brief instant before they stopped existing entirely.

“The key is only destroying what you want to destroy, and not everything around it.”

But between Loki and Thanos, everyone in this reality was going to die soon enough anyway. It shouldn't matter.

It shouldn't.

He might as well use it here as in the Gap—from the Gap, without the buffer any bit of Reality provided, it would rip holes through the multiverse's superstructures, destroying more realities than just the one. Probably. If his math was correct. Idly, he wondered why Thanos hadn't tried doing that. Maybe that's what the Elder Gods were so grimly set upon preventing him from doing.

But Thanos would succeed in the end...

Tony's finger twitched. Settled on the Nullifier's trigger, then lifted away.

A thought was all it took: black light surrounded it and whisked it away, locking it back up safe and sound in the subspace vault. Tony laid his head down in the ash and cried.

 

* * *

 

“You gave him the Reality Gem.” Fury had already paused the debriefing once so he could bark out orders about changing out codes and implementing contingency plans, but against this latest bit of news he just leaned further back in his chair, his eye half-lidded with weariness. It made him look old.

_He can join the club._

“The Mind Gem’s powers are total, like all of the Infinity Gems. Steve, you can’t blame yourself,” said Sue. “There is no one to blame except Loki.”

Fury shot her a barely-concealed glare. “Ms. Storm—”

“ _Dr._ Storm,” Sue corrected coolly.

“—do not think I am _unaware_ of where the fault lies, here.” The carefully controlled anger in his voice had petered out by the time he got to the end of the sentence, and he just looked tired again.

“Sir—”

“Shut up, Captain. I ordered you into that situation; I take full responsibility.” His eye wandered over the rest of the room, lingering on Natasha and Tony. “We prepare as much as we can, but we all know that alien forces can and will have surprises up their sleeves.”

Tony held himself very still. Was Fury having second thoughts about what they’d reported on Gaea? The debriefing continued, and Fury’s eye gave away nothing more about his thoughts. Tony’s attention skittered around mercilessly until he finally comm’d Natasha with the question, but a slight shrug was all he received in return. She didn’t know either. Beneath an illusion, he scrubbed at his face and forced his thoughts elsewhere— _anywhere_ elsewhere. Onto new, non-causal, non-linear, time-space-frequency equations, relations, trying to thread out some sort of logic that made sense... as much as could be made, when formal logic was breaking down.

“—It broke?” Sue asked in astonishment. “That’s impossible.”

“I saw it happen,” said Steve. He was still standing wooden, parade rest—debriefing posture. Miserable. The debriefing had moved on, past a side-digression into the SWORD protocols broken when Steve and Tony hadn’t returned directly from 3490, and into the second, equally disastrous trip to Maklu.

If Tony had been thinking clearly at all, he’d have warned Toni to keep an eye out for Loki with the Space Gem. That level of awareness had taken him hours to get used to, but with instruction, she might have done better. He should have told her how, at the very least. He hadn’t been thinking at all, and their deaths were on his hands.

_It didn’t happen._

“Physical force can’t break an Infinity Gem,” said Sue, with all the authority of a physicist convinced she was right. “The only way to break one is to force it out of its reality: cross a portal or try to use its power across multiverses—or use the Ultimate Nullifier on it, I suppose. But they can’t just be crushed in a fist—they aren’t actual physical objects. That’s just how we perceive them. You can’t physically break an abstract concept.”

“It broke,” said Steve.

“Then something else was going on.”

_The Space Gem is not a point._

“There were at least three other Gems there—Mind, Space, Reality—”

_How do you break a point?_

_You don’t._

Equations clicked in his head—and countering ones, ones that said it was _impossible_ , but if he took them and fiddled with them then the impossible became possible, reality reflected into unreality, where the rules changed until they didn’t _properly_ exist, just like the Time Gem hadn’t really existed, not while in was in the Gap. And he’d been looking at this type of math for _months,_ but he’d never considered it for the broadest set of paired spaces of all—“Transform of the Dirac delta,” said Tony.

“What?”

“How do you break a point? Run the Dirac delta function through basically any transform, and—?”

“—Its transforms aren’t points.” Sue was following; she was frowning. “That’s a math trick. It doesn’t describe the fundamental _concepts_ of ‘eternity’ or ‘infinity’.”

“But it can describe reality.”

“Not _really_... but, fine. To _transform_ a concept, in philosophical terms, you apply—”

“Another concept,” said Natasha, and Tony blinked at her. “Like Steve said—three other Gems—”

“No. No, it was the transform. Physical, practical—a transform is from one space into another. Reality into unreality, or back.” The Gem had been breaking—

Was that what this was? Not the Gem breaking, but unreality bleeding into reality? A fatal flaw, one that caused a function to coexist with its transform _in the same space_. A point in both spaces meant that it was an infinity in both spaces, too. A unique line that was no longer unique—

A window opened up in the air above all their heads, the edges of it crackling with energy. Through it was Reed’s lab, tilted at an angle: the corresponding window on his side must have been above his head and tilted down, too. Reed’s neck stretched upwards, until his head was positioned in the centre of the window, as if they were just video-chatting. “Sue. We need you here.”

“Reed?”

“A ship just appeared in high orbit, halfway between Earth and the moon. Readings put it at the same origin as the one that attacked 294010, but this one’s much bigger.”

“That one was the size of Manhattan,” said Fury.

“This one’s the size of New York State.” Reed's head stared down at them. “Will your Earth assist ours, Director Fury?”

Fury’s expression was unreadable. Everyone else had tensed. Which way would he fall? They’d barely had time to start meeting with other Earths, let alone get plans of attack set up, tech developed, but here they were again.

Maybe it wasn’t coincidence. Something in the world seemed to click together; code uncoiled in Tony’s head, running memory searches and pointing to one answer. “Loki,” said Tony. “Son of a bitch.”

“Stark?”

“He’s backstabbed—I don’t know, anyone stupid enough to trust him, the other gods? He’s sold us out. To Thanos. This can’t be coincidence, we run smack into him and manage to get away and _right_ after that one of Thanos’ ships shows up?”

“Tony.” That was Natasha, the voice of reason and logic. “You’re kind of biased, here.”

“This isn’t _bias_ , it’s data—you don’t really understand how big the universe is, do you? _It was him._ ” He pulled the helmet closed, faceplate surrounding him—armour fully ready. _“Do you really think Loki’s not the kind of guy to make some sort of backstabbing, back-door deal?”_

She inclined her head, a non-verbal ‘ _fair point_.’

“Right now we have a more immediate problem,” said Sue, standing and shoving her chair back from the table. “Reed, have you put a call out to—”

“It’s in progress.”

“Director Fury. Will you help us or not?”

Fury looked at Tony, measured, but it was a lot easier not to flinch when he was wearing the armour and didn’t have to make eye-contact. Tony let his attention hop sideways instead, into 3490, angling in on the unusual gravity blip sitting in the earth-moon system. There was the slightest hint of that _Presence_ that had been there when the Window of Time was destroyed in Maklu... Thanos wasn’t fully there. Was Loki there? A triple-cross—Tony wouldn’t put it past him. A straight double-cross, and Thanos should have been knocking on the door of _their_ Earth...

 _Fuck trying to figure his brain out._ That way lay madness. But Loki had double-crossed him: Tony knew it like he knew the feel of the Time Gem, familiar and certain, and probability equations bore him out on that...

“There’s not much help we _can_ send,” said Fury, voice flat. Ouch. That cost him to admit. “But what we have, we’ll send. Captain Rogers, assemble your team.” His eyes lingered on Tony. “All of them that you can.”

Steve nodded, his expression lightening and focusing all at once—a soldier given a battle to fight, no more waiting. “Natasha, if you can get Bruce and Clint—”

“On it.”

“Sue, do you want a ride in advance?”

“Yes.”

 _“Back in sixty,”_ said Tony, reaching out far enough tap her arm, and surrounded them with a cocoon of subspace before dropping them between worlds—with the portal device, not the Space Gem. They fell into Reed’s lab, the position of the communication window now reversed, with Reed’s head blocking their view back into Earth-199999. Sue immediately went over to a console, grabbing a headset with an attached mic.

“That was rougher,” said Sue, frowning. She’d noticed the difference from when he’d transported them with the Gem.

_“Yeah. I took a look with the Gem—Thanos is... sort of on that ship. Not fully. He’s not committed.”_

Reed drew back his head enough that they could all see each other. “So he might not know what he’s looking for?”

_“Might not be sure it’s here. If we can keep the Gems quiet...”_

Sue and Reed exchanged glances. “If it comes down to it, our infinity gauntlet may be the only thing that can stop him.”

_“It can’t cross the boundaries of realities, and he can. It won’t stop him.”_

“We’ll consider it a last resort,” said Reed, his fingers—he had deformed his flesh so much that he had dozens of them, now—flying across consoles. “We’ve a few of those. Conventional measures first—we have drones in-bound toward the alien ship, scanners ready.”

On the other side of the screen, Steve said, “Tony—” and Tony activated the portal inducer, flipped back through unreality and out the other side. Yet another transformation... was the movement just aliasing, a mistake coming up from too many transforms and too many interactions? A different way to look at it mathematically, perhaps—one that he didn’t have time to look at right now. “Hi,” said Steve, as Tony appeared beside him again. “Bruce will come when he can—he's working on something in the lab—”

Tony checked. _‘Something’_ was turning Jane's lab upside down; she'd been hustled away into quarantine.

“—are you going to be more useful there, or with us?” As Steve spoke, Natasha was double-checking her weapons, and Clint had entered the room sometime while Tony had been dropping off Sue. They were ready to go.

“Over here,” said Reed, his head filling the screen of the inter-reality window again. “Anthony, you have invisibility cloaking on your armour—we have a plan.”

“Let’s go,” said Steve, and Tony dropped them out of their world.

 

* * *

 

“It has RTF modulating shields,” said Reed, pulling up a hologram of the enemy ship. It hovered over the table, a malignant event when constructed of nothing but light and air. “They must have an AI running them—they’re evolving more rapidly than I can program work-arounds, and the occasional drone that has gotten in is taken out by inner defences before it can breach the hull. In order to get a direct strike on the ship, we’re going to need to get inside directly.”

 _“There’s a mass limit to what I can take with me,”_ said Tony, his voice filtered and distorted by the armour. Even with it on, he had his arms crossed over his chest, defensively. _“I’m not going to be able to carry a big enough nuke to cripple that thing.”_

 _“Fortunately, we’ve got something better and smaller than a nuke,”_ said the hologram of Toni that was hovering over one of the chairs. _“A teleport field.”_ A trio of devices joined the holographic ship. _“I’m finishing fabrication now.”_

_“Shields won’t interfere?”_

_“They might,”_ Toni admitted. _“But this ship is cobbled together out of a lot of different alien tech. I’d give it even odds that either Sue or I will be familiar with some of it. From the inside, we can probably confuse the shields long enough to activate the field, even if we can’t disable them entirely.”_

“Disabling entirely would be better,” said Steve, and Clint nodded, adding, “One point of ingress and egress—”

“As fast as they’re adapting? We’d need to do too much damage, too quickly to make an impact before they could get the shields back up,” said Reed.

“Set up those devices _outside_ the ship, then.”

Toni’s hologram grimaced. _“Unfortunately the field’s max size is about half the ship’s. We’re fortunate that the ship’s flat enough for this to work at all. Tony—your inter-reality portal. Can you use it as a teleporter?”_

_“Sure.”_

“Then let’s go.” Steve turned, as did everyone else in the room. Sue was standing in the doorway, dressed in a dark blue suit and wearing a backpack. A breathing mask emerged from the pack to dangle over her shoulder, the straps undone. “Invisibility and forcefields are my specialty,” she explained to the questioning looks of everyone from 199999. “I can create forcefields strong enough to protect me in space, which none of our ground teleporters can.”

Steve’s mouth went dry. The last time Sue had gone into a combat scenario hadn’t fared well for her. It hadn’t fared well for any of them. And that was half his fault—he’d gotten in her way, and Loki had gutted her for it.

 _“I have an invisibility generator I can use,”_ said Toni. _“Unless you have a spare, man-me? I hate to admit it, but mine’s not quite as good as yours. I’ve never really spent a lot of time on it.”_

_“If we have a few hours, I can fabricate one.”_

“We don’t have a few hours,” said Reed, as the hologram of the ship flickered—and then tiny dots were breaking away from it, hundreds of them. Hundreds quickly became thousands. “They’re launching attack ships. Low orbit defences aren’t going to be enough, we need defenders on the ground. From the records of 294010, they’ll land ground troops.”

 _“Three field generators, three people,”_ said Toni. _“Me, man-me, Sue.”_

“Tony?” Steve asked, when Tony didn’t say anything.

 _“Yeah,”_ came the reply via earpiece only.

Steve nodded. “Alright, agreed. Let us know where the rest of us can help.”

 _“Patching you into our channels now, Rogers,”_ said Toni, above a burst of static in his comm. _“Done. Sue, man-me, you should come over here—”_

 _“199999,”_ said Steve’s own voice in his ear—no, the Steve of 3490. The nines all ran together rapid-fire. _“Good to have you. I’ll stick you on the New York team, if you don’t mind.”_

“No objection here.”

3490, apparently, had people who could teleport, not with gadgets or ancient mythical concepts from the dawn of the universe, but by inborn or learned talent. One, a young man in a burgundy costume, picked Steve, Natasha, and Clint up from the Richards’ building and deposited them on top of the Empire State, giving a salute as he warped away again. Then he warped back—to drop off, no kidding, _jet-packs_.

They had the rooftop to themselves to figure out how to use the things. Over the general channels, evacuation instructions relating to New York came through. Civilians were being funnelled into the subway system, into more secure buildings, off of the upper floors. Police were setting up barriers as military vehicles rolled in. It all spoke of planning and preparation that people from another world would only bring confusion into: nothing Steve could help with. Occasionally, there were announcements pertaining to other cities, too, as they were filled with defenders from 3490 and other Earths.

“Hurry up and wait,” said Natasha, hovering awkwardly in midair. “If we have a chance we need to take this street-level.”

Clint had strapped his jetpack on, tried shooting from midair, made a face, and shut it off to claim a perch on one of the eagles instead. “Think I’ll stick up here.”

“Until you run out of arrows.”

The jetpack controls were actually fairly intuitive, but it was going to be hell trying to fight while wearing one—and while Clint, at least, was used to extensive aerial tactics, that was with _aircraft_. “Street level wouldn’t be such a bad idea,” said Steve, trying to resist the urge to pace. He’d always hated the waiting part. He didn’t even have a full team to worry over, to make sure that they had all their gear before diving in to the fight. He wasn’t waiting for a cue to move. This time, they had to wait for the fight to come to them. If they’d gone with Tony, instead—Tony could have made extra exosuits—

But not extra invisibility generators, Steve reminded himself, and made himself keep his finger off the comm. They were here to help, and right now that meant staying out of the way and waiting.

“Feels weird, huh?” said Natasha, landing lightly beside Steve. “Being unable to call the shots.”

Clint snorted. “Getting too big for your britches, Nat?”

“Just don’t like waiting,” said Steve. He couldn’t keep his eyes off the sky. It was a beautiful day—cloudless, low smog... “Feels wrong.”

“You’d never make a sniper.”

“Never tried.”

An update came over the radio about the general positions of the inbound fleet, and they all paused to listen. ETA, ten minutes. The bulk of the alien fleet was mostly over Europe, still too high altitude for the various allied air forces of the European Union to come into play. But the aliens were splitting up _now_ —aiming for a simultaneous strike when they finally did come down.

“When Hydra wanted to sterilize the world, they tried to bomb the hell out of everything,” said Steve. “These guys have space travel, they’ve gotta have bombs. But they’re coming down here in person. Making it sport. Just like Loki.”

“Their loss,” said Clint. Steve glanced over at him, catching his eyes: focused, intent, and remote. Sniper’s vision.

Seconds ticked by, marked off by the click of the radio, the sounds of shouted orders from the streets below. People were still being evacuated. Taking the fight to the streets right away wouldn’t give them the advantage if there were still civilians in the line of fire. But looking over the edge revealed that the police—some brightly-coloured costumes among them—had the situation well in hand. Full-scale evacuations just took _time_.

“Hel said that Thanos was trying to court her goddess,” said Natasha, thoughtful. Steve remembered that; it had been in her report. There was an ongoing debate among the history geeks of SHIELD about who or what Hel’s ‘goddess’ could be. “Maybe he needs the gesture to be grand.”

 _“New York, incoming in two minutes,”_ said a new voice over the comm, one that Steve couldn’t recognize. _“Everybody, take your building. Air Force’ll try to thin them out before they get into the city, but once they’re in the trees it’s up to us. Stick close to your building and cover each other’s asses.”_

A cheerful voice, disturbingly young— _“Asses will be covered, SIR!”_

_“Kill the chatter.”_

There was a _crack_ of displaced air, and Tony blinked into existence a few feet overtop of the roof, holding onto Bruce.

“Tony? What happened?” Tony was supposed to be getting ready to infiltrate the mothership—had there been a change of plans? “Bruce?”

_“Just playing taxi.”_

“I figured the lab hunt could wait. The Other Guy might be more useful right now.”

“You’re not wrong about that—”

 _“I need to get back,”_ said Tony, and vanished just as abruptly as he’d appeared.

“There we go,” said Clint, and Steve turned—he was staring off into the distance, and following his gaze, Steve could make out small, black specks. A few seconds later, and the thunder-cracks of distant explosions reached their ears: the battle had already been joined. Steve flexed his fingers, feeling the grip and flex of his gloves, re-checking the positioning of the jetpack controls. None for Bruce, but the Hulk didn’t need one. A jetpack wouldn’t have fit the Hulk anyway—Bruce was already stripping out of his jacket and shirt. They wouldn’t fit, either.

 _“Steve,”_ said another voice, much more _present_ than the others on the comm, so much that Steve turned his head to the side, away from Natasha. This one was for him alone: Tony’s, as crystal-clear as if he was standing next to him. _“I... good luck. Don’t get killed.”_

“You too. You going now?”

_“In a few minutes. Figured you’d be busy by then.”_

“Uh-huh. Stay on your game. Don’t get spotted up there.”

_“Yeah. Look. I don’t—I don’t think Loki’s here. But if he... is...”_

God damn it. Steve didn’t want to say it, didn’t want the thickness in his throat, not _right before_ this battle they were waiting on. “I already promised. I’ll keep it.”

_“Thanks. Steve... I couldn’t trust this to anyone else.”_

Because Steve was the only one that _knew_. But somehow... that didn’t make the sincerity in Tony’s voice any less real, nor erase the sentiment beneath the words. It didn’t help with the tightness in his throat. “Just come back safe.”

 _“Likewise, Cap,”_ said Tony, and the connection ended with an audible _click_.

He looked up to find Natasha giving him a level look. “Considering everything that’s happened,” she said, “it would be really good to know what you _promised_ Tony.”

Nearer, now, US jets raced across the sky in the distance, and shot down and were shot down in turn by far more manoeuvrable alien escort craft. Less wieldy craft was on a straight line for the city—two were struck by missiles, raining debris down over the ocean. Some of that debris altered its trajectory and started a sharp descent toward land instead—live cargo. And another carrier was nearly over Manhattan, now—

Something like a blazing star struck one side of the nearest carrier and rocketed straight through, out the other side, burning sun-bright. The carrier listed; the star doubled back, up to underneath it, and resolved into the shape of a person, single-handedly keeping the ship from crashing the city below. But smaller engines were igniting along the sides, one- and two-person craft breaking free of the larger ship and angling down for New York, hunters fixated on their prey. The aircraft didn’t look much like the Chitauri’s—less open, more winged—but the concept was the same.

Beside Steve, bones creaked and _popped_ , skin bulging and growing with the noise of flesh strained to the limit. Fabric ripped and tore. Steve glanced over and looked into large green eyes, a flattened face, and a bloodthirsty grin.

_Wait’s over._

He twitched the controls for the jetpack and hurled himself into the sky, towards the death raining down. Shield up, first target decided, Natasha right beside him and the Hulk hurling himself skyward below them, Clint providing cover—“I promised him he didn’t have to go it alone!”

 

* * *

 

Thanks to Bruce’s work on their wonky math, the SWORD portals could also be used to teleport between two points in the same realm. Tony’s method of falling into the Gap wasn’t quite so allowing: when he didn’t set the end point far enough from the beginning, they simply combined, so that he had to flip in and out of realities in order to teleport across the room. Sue, on the other hand, had a whole range of teleport technology available in the Baxter Building, all designed for hops in 3D space... it was just that when they tried, none of it could get past the enemy mothership’s shields.

So they went in via Earth-199999, landing in Ohio for a brief moment so Tony could reconfigure and flip them back and into the blackness of space.

Toni hadn’t been speaking with false modesty when she’d mentioned that her invisibility cloak wasn’t as good as his; it was an imperfect chameleon. But no perimeter defences immediately vaporized them, so it had to be good enough. He couldn’t tell that Sue was there at all.

_“Sue?”_

_“I’ve arrived at my coordinates,”_ she reported via radio. _“Teleporting works just fine inside the shield.”_

None of his scans had picked up that she’d even used the teleporter. Was her invisibility actually absolute? Even his upgraded ICG left the faintest of traces, areas where things didn’t align properly and a detailed enough scan could detect anomalies—anomalies that he scanned for regularly, these days. But she hadn’t shown up at all even when teleporting, and teleporters weren’t exactly subtle tech.

 _“Go on, man-me,”_ Toni told him. _“I’ll be fine hanging out here.”_ The movements of her armour registered vaguely in the back of his mind, even if his scans couldn’t make out more than her general location—jetting toward one of the massive structures on the hull.

They all three of them had local teleporters that Sue had provided. Tony used his to flicker over to the third point—an abrupt, jarring movement—and pick out a spot to land by the light of the Earthshine from above. The completed teleport field generators were shaped approximately like cylinders, each with a thick base that was designed so that they could be welded securely to a surface. That was his and Toni’s job, with their pillars; Sue could apparently hold hers to the half-degree max angle required with force-fields alone, even if she herself were unsecured.

Given a spaceship the size of New York State, the weld jobs might not even be noticed.

_“Ready.”_

_“Go.”_

As soon as the blue light from his wrist laser started melting metal, the hull shook beneath him—not violently, but too much to make it a good spot. Tony swore. _“This substructure’s unstable.”_ It couldn’t be the entire ship shaking—that would be too much mass shaking at too high a frequency. _“I’m picking another one.”_ If the same thing hadn't happened to Toni, then it wasn't a reaction to the weld. Unless he’d been _really_ unlucky in picking his spot, and had just doomed them all.

_“Make it fast.”_

He pulled back and skimmed along the hull of the ship, mindful of the max radius, and dropped into a superstructure that was like a canyon—launching bay for all those carrier ships, maybe. The Earthlight here was mostly double-reflected, the walls blocking much of it out, but he was still definitely _outside_ of the ship: scans picked up movement, but it was all on the opposite sides of metre-thick walls. He’d be able to see things coming. But just to check, he rapped it sharply with one fist.

A larger chunk of space debris collided with the side of the ship, which didn’t detectably change momentum from the blow. It was simply too massive. Tony steadied the field generator against the hull and lit his wrist laser again. He did a test score first, to give his sensors enough to read the metallurgy by, and then adjusted the output and began the weld. It went quickly—this was not a job that needed to withstand the passage of twenty, thirty, forty years. Fifteen minutes would be more than enough.

“ _I’m done,”_ Toni announced. _“Status?”_

 _“Having difficulty finding what I need,”_ said Sue. _“Their mainframe is something new—it’s not interfacing with anything I’ve brought with me.”_

 _“I can try—damn! I can’t, I’ve been spotted,”_ Toni said. Her voice was calm—it was a mental uplink; it didn’t matter if she’d taken fire or needed to move quickly, if she could keep her thoughts level. _“Yeah, try and get through_ that _force-field, bastards._ ”

“I can try,” said Tony. The words reflected back to him from the confines of his helmet, completely separate from the comm message he’d sent to the other two. His weld was finished—the pillar only needed calibration. He set his palm against the hull and activated the local teleport band, flipping through space and into the interior of the ship.

It was cramped. He cut the repulsors and fell a few centimetres to a surface, caught in the grip of artificial gravity; the modified Foster Silencer kept the sound of metal-on-metal from being transmitted through either what he’d landed on or the artificial atmosphere. There was metal directly in front of him, too: it was as if he’d landed in an air duct, except it wasn’t a tunnel—he could move up and down, left and right... just not forward or back. He was stuck between two massive metal plates.

Or two metal _hulls_ , Tony realized, and suddenly the sensory data he was getting, distorted by coming around corners, made sense. He activated the teleporter again, taking himself about a hundred metres over, and then another hundred, until he was out in open space, hovering over the troop carrier that was wedged nearly up against the wall of a truly _massive_ docking bay. On the floor, a conglomerate of different species of aliens ran to and fro, all with military aim and zeal, performing maintenance or readying weapons as their roles required.

Some of them looked like the Chitauri. Most didn’t. Pattern recognition picked out markers, likely indications of rank, scattered across all the species: an egalitarian outfit, then. United by genocide.

Before he could manage to identify possible access consoles, an alarm began to blare, sending the aliens scattering in an orderly fashion; this was something they’d been expecting, not an emergency or an unexpected intruder alert. Tony made himself stay still despite the adrenaline rush. There was the tell-tale warp of force-fields engaging, cutting the rest of the bay off from the ship he’d come in on the far side of, and its three nearest sisters; they were closing their own hatches. None of the tech chatter that he could pick up made any sense to extremis, but he didn’t need it to know that they were preparing to launch.

“Wait two minutes, they’re going to punch a hole in those force-fields on their own. They’re sending out more ships,” Tony said. And then—“Oh, _shit_.”

The massive hanger door was opening, retracting upwards. The massive hanger door—the outside of which he’d just welded the field generator onto. No _wonder_ it had been clear, nothing around; it was a _door!_ And it was _moving_ , damn it!

_“What?”_

_“Anthony?”_

“Need to reposition it, _again_ ,” Tony said, trying to teleport back—only for the teleport device to spark and die. Of course: the atmosphere was rapidly decreasing, but not as quick as it should have with that much open space—they were doing a rapid, but still controlled decompression, while the door was open, which meant there had to be a force-field between them and the outside hull, and they’d already figured out that the aliens’ force-fields could block their teleports.

Tony swore and pulled up calculations for the inter-reality portal device, dropping himself back home and a kilometre above the Hudson River. Then more calculations, while a much smaller part of his brain ran much simpler math—the weld was a minute job, considering the rate of the door retraction there was no time to properly de-weld, so just wrench the damn base off and don’t crack it in the process—he hurtled through the Gap and popped back into existence outside the bay door, then made a beeline for the field generator. This time, when he used the wrist lasers, he didn’t carefully modulate the heat; he reduced the surrounding metal to slag and pulled the field generator free before rocketing away. He was too near the edge of the field generator’s radius, and the damn docking bay was too _large_. The motion of the door was causing _everything_ to vibrate.

No air resistance in space: he accelerated at a brutal pace and was two kilometres further in barely a second later. It was the lucky day of those aliens in the outer half of the docking bay; they weren’t inside the perimeter. Considering the interior force-fields the ship had, they might even survive what was about to happen. Tony landed and started welding again immediately.

“ _Not to rush, but I’m taking fire here.”_

“ _I have mine stabilized. Anthony...”_

The weld was shitty, shoddy work. It’d last for five minutes. “Solid. Go for it.” Tony concentrated, and let his brain slip into the inner workings of the field generator, working to rotate it into perpendicularity with the plane drawn by their three points. Sue’s was the reference point: Toni and he could do this by thought alone, but she needed equipment to be able to align hers. On the other hand, she didn’t have to risk goddamn shitty luck with her location, either: she was floating free in space, holding it up with her mind.

A massive shadow passed overhead, momentarily blocking out the Earthlight. The carrier ships were leaving—hundred thousand more troops that they couldn’t stop _here_ , moving to bring death and destruction to the Earth up above. “Window’s coming up—”

“ _We’re in alignment. Get clear. Activating.”_

He hadn’t been stupid enough to be standing inside the ring, but he threw himself backwards all the same, up and out on an angle that brought him beneath another carrier’s shadow. The field generator, now outside of the shelter of his ICG, lit up like a beacon—literally and on all frequencies, screaming with electronic noise. The automatic defences of the mothership took note. Turrets rose out of the surface of the hull, and fired with machine-precision accuracy at the fragile, defenceless generator.

The explosion from the field generator being ripped apart by the bolts generated no noise. Neither did the sudden, gaping emptiness beyond it. Half the ship was gone, teleported one hundred and fifty million kilometres away by the teleport field the three pillars had established. That was a pittance in terms of interstellar travel, and even more so considering that this fleet probably hadn’t come from this _reality_ , but Toni had aimed the field very precisely, and one hundred and fifty million kilometres was all they needed.

The centre of the sun burned a hot fifteen million degrees Kelvin, and even Thanatosian shields weren’t designed to stand up to that.

In the distance—mere hundreds of kilometres away—explosions bloomed outward from the back quarter of the ship. They were much like another explosion in space he’d been responsible for, once, except that this time it was many thousands of nukes, all exploding spherically, overlapping. That had been near Sue’s point, given to her because she didn’t need to worry about vibrations throwing her field generator off, and so could stick one right in the middle of the massive lines of primary engines. Thousands of engines, together powerful enough to propel a ship this size—and all those engines had just had their containment vessels shattered when their front halves had been ripped away by a teleport field.

The field generators could only cover a distance equal to about half the ship, but there was nothing like a little ingenuity to let one add to the death toll. Not that it would make much of a difference; at this point it would be a drop in the bucket. A ship the size of New York State had one hell of a crew complement, and they'd just slaughtered half of them.

_They were all enemy soldiers, engaged in genocide..._

_Christ._

“ _Job well done,”_ said Toni, subdued. _“Outer shield is still down. Reed’s sending up another wave of drones to deal with what’s left.”_

Beneath Tony, the portions of the hull still intact began to splinter. But... these breaks were too clean. Not quite a straight grid, but only because that wasn’t the most efficient way to divvy up an object with irregular edges. Tony jetted further away, watching cracks form along pre-designed faults until chunks of the hull fell away, split into neat little cuboids and prisms... and each, individually, _turning_ , sprouting wings and claws. A monstrous mechanical swarm.

“ _The ship’s activating a suicide trigger!”_

“ _Reed, we need more drones—no,_ all _of them, look at what we’ve got up here—”_

Through Toni, Tony could see the numbers line up; she was in contact with Reed, hooked into his battle simulations. Red dots for enemy ships, blue dots for just-launching friendlies, and even a glance was enough to see that there was nowhere near enough of the latter. A ship the size of New York State, even cut in half, was just too much mass.

Then the amount of mass in the battlefield increased by one-fifth again, as thousands of wormholes opened and closed, depositing sleek, silver ships that appeared almost spherical but whose hulls were each comprised of millions of flat planes: mathematically perfect craft, right up until they all sported very practical guns out of those planes, and canon-fire began blasting apart every Thanosian ship on screen.

Including the ones beneath him. Tony barely evaded one beam, almost crashed into the path of another, and ripped himself away—back to the Hudson in 199999, and then right into 3490’s Baxter Building, dropping his invisibility as he went. Around him were a dozen brightly-dressed people, all cheering at one of Reed’s screens, where an only-vaguely-human-looking Android was demurely saying, _“—be of assistance to you.”_

_Huh, whaddya know. Their allies came through._

 

* * *

 

It took Tony nearly an hour to stop waiting for the mantra to repeat.

Not that he stopped _expecting_ it, after that—if something further had happened to Steve, or if Loki now knew it, then there was no telling... but. But. Extremis was putting up pointed reminders to him, of low external temperatures and falling core temperatures, and finally either his natural aversion to listlessness caught up, or maybe Gaia's remedy kicked in.

 _Gaia. Fuck._ He took another second to laugh, and tried not to let it become a sob; he'd done enough crying for today. For the rest of his life.. Was it Gaia's fault—her and that damned magic water—that he couldn't quash the thoughts turning over in his head? That he couldn't just _give up?_

“Fuck,” he whispered. He rolled over, flat on his back in the ash, and stared up at an alien sky. Three suns beamed down from overhead, but they were all tiny, far off. The fact that this planet existed in human-habitable temperatures around a trinary system should have been interesting. It wasn't.

At length he sat up, scrubbed his face, and pulled extremis around him. He'd lost a critical mass of the armour's nanites somewhere along the line, and what remained were mostly lying inert on the ground, but it was simple enough to pull more nanites out of subspace storage. Extended prodding got them formed into a slimmed-down version of the armour, and kicked his internal systems hotter until the biological components stopped protesting the low temperatures as much.

Grit itched against his skin, and he set the inner-armour nanites to clearing it away. Already, the outer surface of the armour was covered with the fine, wind-blown dust. By contrast, the Gems gleamed preternaturally bright, their colours undiminished, like the dirt couldn't touch them.

He contemplated dropping them back into the dirt. Leaving them here, permanently. If he took them back—if he tried to take them back to Earth, Loki would, no doubt—

_I can't bring them back._

That would be handing them over to Loki, and if it had been Loki—it _had_ to have been Loki—who had used that mantra, if it hadn't been Steve—if he handed those Gems over to Loki, then Steve would be right to use the mantra in turn, because he'd have fucked everybody over.

He realized he was shaking. A moment of writing code stopped the physical reaction.

_I can't go back at all._

Loki would—if Tony came back, and Loki came for him and the Gems, and he _didn't_ _have them—_ no. He shut that thought down ruthlessly, dismissing the entire possibility. He couldn't go back without them. _I literally can't. I don't know where the fuck I am._ He'd run without thought, depending on the Gems to do so, and now even if he could figure out _where_ he was, _even if_ he could use the inducers to get back home—he'd come adrift in Time, too. He didn't know _when_ he was, and he didn't have a time machine, or the first clue of how to build one. If it was even possible, outside of artifacts like the Gem.

 _I can't go back._ Not without some way to counter the mantra. His brain flinched away from the thought of trying to get rid of the headband, warned by a flaring headache that subsided as soon as he made frantic conciliatory thoughts at it. He'd always known that, going up against Loki, he'd need a weapon that was bigger, more destructive, _faster—_ now Loki had a weapon that was as fast as thought.

He'd promised Steve he'd trust in his fellow scientists, in his _teammates_ , to step up to the challenge when he couldn't find the solution. But... Steve was gone. Loki had grabbed him. Tony was stuck out here alone.

He couldn't rely on his teammates to take down Loki.

_How do I out-think a god?_

There was no point to it, when even discounting the mantra Loki had a brain twistier than a den of snakes. Loki'd sent Tony after the Time Gem; if Tony came back with it speeding up time around him, giving him more space to think, no doubt Loki would be prepared for that too. He'd know about the Space Gem—Chthon and Oshtur had said he was after all of them. He'd grabbed Steve, set that program—no, he would have traps waiting. There was no _point_.

“No,” Tony whispered aloud, stopping himself. Or maybe it was Gaea’s fix that stopped him. “No.”

He hadn’t tried before, had evaded the problem entirely by refusing to cooperate—but he’d still wound up here. Not _trying_ to outthink Loki didn’t work; it was still an action, and Loki had wound up controlling the field once again. His refusal to play was still a move in the game. There was no escaping it.

“Act or don't act. Both are choices.” He'd told Steve that, accused Steve with those very words. He was an idiot and a hypocrite.

_God fucking damn it._

Think!

He had the Space and Time Gems. Loki would have a trap of equal power set up—most likely the mantra—waiting for him to bring back the Time Gem. Waiting for Tony to bring him a weapon.

So, then... he’d have to bring back an _arsenal_.

And that was, surreally, the most reassuring thought he'd had in ages. _I was the goddamned Merchant of Death._ He'd hated that title, but he'd hated it because it was true. _I can do arsenals._

He _had_ an arsenal, pocket-nukes upgraded to god-tier. But more WMDs weren't what was called for, here, not when Loki could drop him before he had a chance to fire.

An arsenal suggested a set, which suggested the Gems. There were others still out there—at the very least, the Soul Gem, which another world's Sorcerer Supreme had suggested might be a fragment of a once all-powerful God. Between Space and Time, if there were more fragments out there then he _should_ be able to find them. Somehow. Shouldn't there be some sort of resonance, some sort of connection he could use? He'd thought, just before he crashed here, that it had felt like someone was trying to pull on the Time Gem using the Space Gem. Using the Space Gem to search the entire multiverse was out; the information overload was too much. It wasn’t like using the Window, which had had its own search function. Would using the Time Gem be like using the Window? He had nothing to lose by trying.

_Except maybe my sanity._

A lost cause already. He curled his hand into a fist and focused. It was easier than it might have been: he didn't know whether to chalk that up to Gaea's brew or not. Afghanistan had been like this, that moment when he'd considered the seven days remaining to him, the most important of his life, and realized that the energy of an arc reactor could fit in the palm of his hand.

Now he held eternity and infinity, and it was much the same.

 _Show me your past,_ he told the Time Gem, and it obeyed.


	18. Mind and Matter: 4.3

The history of the Time Gem was the history of the multiverse, gathered up and curled in on itself in increasing powers of tangles.

 _Show me your past,_ Tony told it, and the Time Gem obeyed: it yanked back against an outside force attempting to exert influence. It brought its user forward through time. Its pieces were being gathered up in reverse, and as each was ungathered his mind spread further across the Gap and reached that series of simultaneous points, all the loops from the Window of Time stacked on top of each other—

One dead—

One hundred million dead—

Ten thousand dead—

Ten billion—

 _Wait, these are in the wrong direction,_ Tony thought, and then realized it didn’t matter to the Time Gem. It showed him: all of Maklu dead, and the Window returned into a whole, orange light sealing the cracks—

Ten million dead—

Four hundred thousand—

 _Earlier,_ Tony demanded before he could lose what was left of his sanity, and the Gem pulled his mind along with an iron grip, earlier into the past. Events that weren’t causally coherent flashed past, spikes of power and _there’s a pattern here_ that he couldn’t understand. His body, some eons into the future—at the same moment—deep in the past—tensed, his grip on the Gems shifting. There was a pattern, and more than that, there was _something wrong._ The Gem's own history showed fault lines, and the one in his hand had broken in multiple separate places, multiple separate times, energy spilling over along those fault-lines as he looked: not at the physical events, but at the luminous stars that were the Gems themselves.

 _Gems_ , he realized, plural: other Space Gems, other Time Gems, and Reality warped and rang like a bell, a wave that rolled up and drowned him.

Tony opened his eyes and found himself flat on his back. Systems-check came back clear but with a warning that he'd probably lost time. _No shit._ He had a Gem in each hand, and a layer of ash had settled on him, which shifted and drifted off of him as he sat up. A check of the sky showed that one of the suns had set.

All-in-all, it hadn't gone too badly.

_Okay, let's try that again,_ avoiding _the catastrophic system-failures this time._

The foreboding question— _and how big is that system?_ —he buried. For now. Instead he stared grimly down at the Time Gem and thought, _Earlier._

 

* * *

 

Steve’s mental clock told him that it had been about forty minutes since contact. It felt like a lot longer, but sustained fighting always did. Every hit took its toll, both the ones he gave and the ones he took, adding up to a weariness that even the serum couldn’t cut. At his back, Natasha was breathing heavily—by now she had to be running on pure willpower alone. Clint, up on his perch, kept running out of arrows, but 3490 had a system set up to resupply snipers, so he was in better condition than either of them. They’d lost track of Hulk within the first ten minutes, but every so often his roars echoed out over the warzone. Him, or some other version of him: there was at least one red version running around. That one had jumped in to intercept a crashing glider before it could pulverize Steve, given him one of those toothy grins, and then used the glider to pancake a group of approaching aliens before jumping away again.

After Tony had reported back as safe, Steve had hoped he'd join the fight with them, but Tony had elected to stay at HQ instead, ‘looking into other options’. To keep Tony away, it must have been urgent. Battling aliens in the streets of New York, the absence of both Tony and Thor felt bigger than it should have, considering how many other costumed superheroes were taking part.

Fortunately, the fighting was now just mop-up: the destruction of the mothership and the arrival of the Android fleet had been announced not just via comms, but by loudspeakers from the front of National Guard tanks, their message echoing through the streets. Whether the aliens spoke English, Spanish, or Allspeak, it had seemed to dampen their spirits nonetheless; chatter on the comms was now less triage and more focused on how to secure prisoners when some of those prisoners had ten limbs, all of them double-jointed.

But his team’s street hadn’t hit that critical shift yet. Steve leaped up a parked, dented car and flipped sideways, adding momentum into the spinning kick that drove his heel into the skull of one (bipedal, in this case) alien, while tossing his shield at in the opposite direction. Cries of pain and the shield’s unique song let him keep track of its path as he landed in a roll and kicked his feet out, toppling a second alien and tangling it with the body of the first. He held out his hand just in time, catching the shield as a crowd of aliens converged on him, and then it was blocking and dodging, close-in fighting that at least had the advantage of not letting any of them use their energy guns properly.

Not that some didn’t try. Steve chopped down on one long limb, barely deflecting the bolt into its ally; that one shrieked and died while the first one shrieked and clutched at its mangled arm. Steve kicked it away, blocked another bolt with the shield, and didn’t manage to avoid another pair putting their guns to use as clubs instead. The suit that Tony had made him was _good_ , but these guys were strong. He grunted at the impacts, too near his kidneys, and dropped to the ground with a low, scything kick that broke one’s knee and tangled it with the other.

On the downside, that made it easier for a couple more of them to jump on him, all of them intent on pummelling him into submission.

A booming voice echoed off of the buildings. _“EVERYONE DOWN!”_

Steve was already down. The aliens all glanced up in alarm, and he took advantage of their distraction to pull his shield up to cover his head. Then crackling scarlet energy exploded overtop of him. For a moment it turned translucent, ethereal, and then long tendrils of now-crimson light wrapped around the standing aliens, tightening and making them _scream_. It didn’t take long, perhaps a second, before they were all falling to the ground dead.

Rather than rise too soon after _that_ display, Steve crawled his way out of the pile of bodies. Some of those on the ground were still moving, making weak noises that he translated into groans. Those were the ones that he’d downed, before that deadly red flare. Peeking over a body, Steve found the flare’s source: a woman—probably the same one who’d shouted—floating in the sky, red light crackling around her hands and feet, the same colour as her scarlet cape. Beside her, a garishly dressed man hovered as well, his arms crossed. Steve took a chance and waved for their attention; they caught sight of him and flew over, landing as he stood. Behind them, Natasha was ducking her head out from her own cover.

“Report in,” Steve ordered over the team channel, and then, to the strangers, “Thanks for the assist.” It came out breathless, loud in the suddenly quiet street.

“Our pleasure,” said the woman. She was wearing a necklace that bore the same strange eye amulet that Anthony and Stephen Strange had worn. A Sorceress Supreme? “You aren’t the Captain America of this world, are you?”

 _“Hawkeye here, I’m good,”_ Clint’s voice said in his ear, overtop of hers. _“Got a bead on our Hulk, too—he’s having fun over on Second. Nobody’s moving much here but your two friendlies, but we’re gonna need the Guard to start taking prisoners before that changes.”_

“Noted,” Steve told Clint, grimacing apologetically as he returned his attention to their new allies. “And sorry, no. 199999.”

“Ah,” said the sorceress, her expression showing she obviously knew just which Earth that was. “I am Wanda Maximoff, Sorceress Supreme of Earth-83437. Your team is well? I’d planned to go first to wherever headquarters are, and see what aid is needed.”

“Widow here, fine too,” said Natasha, tapping her comm so that Clint could hear as well. “Cap, you should go with her and check on Tony. I can wrangle the Guard.”

“I shall stay to assist,” said the until-now silent man at Maximoff’s side. His voice was smooth, cultured, and very much at odds with his garish green and red colouring. Up close it looked like it was the guy’s _skin_ , however, not any sort of suit or costume, so Steve couldn’t really blame him for the eye-watering combo. “I am the Vision. You are Natasha Romanoff, also of 199999?”

“Agreed,” said Maximoff, as ‘the’ Vision and Natasha exchanged politely wary nods. Steve gave Maximoff one that he hoped was less wary, and then Maximoff turned and kissed the Vision on the cheek, close to the corner of his mouth. “Stay safe, dear. Captain, please concentrate on the image of where we are going... ready? _B_ _y this light of day, there we shall away!”_

The world wrenched around with grasping scarlet energy, and then they were in Reed’s lab. By-now-familiar blue force-fields shimmered into place, and then dissipated a moment later as Sue’s voice said, “Building, override that. Steve, everything all right?” Steve turned to see Sue nearby, a table between them. She’d traded out her earlier expedition gear for a lab coat and gloves, although she still wore the same dark blue uniform underneath. The table in front of her had a holographic projection of some kind of very complex-looking machine, the possible function of which Steve had not a clue.

“Yeah. Fifth Ave’s clear, thanks to, um, Ms. Maximoff, here.”

“Of Earth-83437,” said Maximoff. “I am sorry we did not catch the word sooner. Where may we best assist?”

“You’ve got your own communicators? Toni, do you mind patching her in—”

Steve couldn’t see where Toni was, but she must have been listening from wherever because a moment later, Maximoff tilted her head to the side, and Steve’s ears picked up the faint radio chatter from the comm she was wearing in her left ear. “Thanks,” Maximoff said with a smile, and gave another smile toward Steve before turning away with a hand to her comm, asking for directions.

Steve tuned out the sound of his own counterpart’s answer. “Sue, is Tony, my one, still here?”

Sue shook her head. “Sorry. He went to Stark Tower with ours. She’s got some idea—I don’t know. The trick we pulled might work a second time, but I think it would be pushing our luck. Udarnik’s fleet was pretty pressed against the remains of this one. He hasn’t had enough time to crank out anywhere near the number of ships we need yet.” Even as she spoke, she was adjusting things in the holographic machine, continuing her own work, but she nodded to one of the screens that Reed—a part of Reed, anyway, and boy was _that_ unsettling—was hovering over. The grey Android on the screen did not appear to be perturbed by the oddness of his conversational partner, however. Or maybe he just didn’t look at the video feed.

Either way, 3490 had made a good call in trusting that world.

Steve nodded his thanks to Sue and turned away, flicking his comm back to speak on the team channel. “Stark, check in.”

_“Present. Busy.”_

So noted. Steve glanced around the lab again—filled with people wearing far fancier headsets than his, coordinating the defences, working on solutions. He wasn’t needed here. He caught Maximoff’s eye, but she was busy speaking over the comm in grimly unhappy tones—“...not a matter of opening doors, but getting them closed again without—”

“Heads up!” someone called, breaking the chatter in the room.

Reed’s head twisted around nauseatingly. A few gestures from his over-many fingers, and a projection of the Earth and the space around it filled the centre of the screen. Blue dots hovered in space, tagged with information and symbols approximating the look of the Androids, a comforting visual of the reinforcements.

Then the number of dots doubled, and doubled again. After a moment, the new ones all turned red, and adjusted in size and shape. Most of them were quite a bit larger than the blue dots.

“Ah,” said Reed, fingers dancing as he flipped through screens filling rapidly with more detailed information. “Udarnik, you have a problem up there.”

The Android’s voice was calm. _“Yes. We see them. Repositioning to engage.”_

“You’ve got less than a twenty percent chance of surviving against a fleet of this makeup—”

 _“Twelve-point-three,”_ Udarnik agreed. _“We will buy you time. I recommend you evacuate your people, Earth-3490.1025. You will need every second.”_

“Udarnik—!”

 _“Engaging the enemy,”_ said Udarnik, and his voice had changed, becoming deeper and more metallic. Edged. _“Shockworker out.”_

“Damn it!” said Sue. “We need to expand that field size—”

“To get it _that_ large would have some unpleasant after-effects for our Sun,” said Reed. It was impossible to read his expression, but his voice was calm as he switched to general broad-cast. “All points, this is Baxter. We have a Code Eight. I repeat, we have a Code Eight. Commence the evacuation of Earth.”

“You’re calling it too early—”

The display flickered. Lights were going out. More red lights appeared... more blue ones did not. Steve nabbed a free terminal and fiddled with the controls, trying to get the information he wanted. There were no more enemy ground troops landing, not now. Evacuation procedures were easy to find; they were front and ready for anyone who might need them, except that even a glance was enough to see that the necessary preparations couldn’t possibly be completed in time. “You’re not ready.” How could anyone be ready to evacuate seven billion people? Through highly advanced portal technology that 3490 hadn’t managed to finish building yet, apparently. He tapped his comm. “Tony, can you evacuate them?”

_“Seven billion? No.”_

“Show me these plans,” Maximoff demanded, joining Steve at the console. “I can teleport some, at least.” Some—she’d blasted a street away. But that was nothing compared to what they needed.

He showed her, anyway, and her face fell in dismay. “Oh, Gaea...”

“Reed, we need the gauntlet,” said Sue, pulling her gloves off. She pressed one bare hand against the holographic table she’d been working at, and a compartment popped up in the middle, one that opened when she pressed her other hand against the side. 3490’s infinity gauntlet lay there, gleaming as the compartment’s sides folded down around it. Sue picked it up gingerly.

There was a _crack_ , and two armoured figures appeared—Tony’s head sticking partly into the centre hologram. _“—weapons,”_ Toni said, obviously caught in the middle of a sentence, and then, _“Goddamnit, Tony, what the hell!”_

 _“If you use the gauntlet he’ll know,”_ said Tony in a rush.

“Attacking this Earth, _right_ after your jaunt? He knows,” said Sue grimly. “You said it—Loki sold us out.”

 _“He suspects—if he_ knew _he’d be here. Don’t confirm it for him!”_

“We won’t be,” said Sue, staring down at it. “This is just the local version.”

_“Still enough to get direct attention, don’t you think?”_

_“He’s right,”_ said Toni. _“And I’ll give you a goddamn virus if you teleport me like that again—but the field generator gave me ideas. Reed, do you still have the Ultimate Nullifier?”_

“Have you lost your mind?” asked Reed. Among all the voices in the room, his was the calmest—the _strangest_ , too, probably thanks to his torso being completely bent out of shape. “Sue, hold off on the Gauntlet for now. It might not draw trouble, but we need the evacuation further along before we take that gamble. Toni, the field generator would be Nullified itself before it even registered the effect, there's no way it could contain the Nullifier.”

_“Right, but with man-me’s inverse portal—”_

_“You’re an idiot—bring the Nullifier into the Gap and it would start collapsing the superstructures of reality!”_

“Using the Nullifier in any way is a suicide move,” said Sue grimly. “We’re not quite—” An alarm blared, cutting her off; Sue reached across her husband’s limbs to slap it off. “Wanda.” Her voice was thick with stress. “A ship just appeared in the sky over your world. And another over 1582.”

Maximoff crossed her arms. Her lips pressed into a thin red line—but a moment passed, and then another, and she did not disappear. “I see. This battle will not be won on one Earth alone. Twenty worlds are fighting here... we need to unite to defend the others in the same fashion. That will be difficult, once we are _all_ under fire.”

 _“I’m not letting it be lost here,”_ snarled Toni, and she vanished with the tell-tale _crack_ of teleportation.

“We need more allies.”

“You need to go home and grab your own Earth’s gauntlet,” said Sue.

“We don’t have a full set of gems. Tony. Steve.” Maximoff looked between them, and in that moment she was familiar: white streaks in dark hair, and a high red collar framing her face. _What made a Sorcerer Supreme?_ Steve had wondered so long ago. _A willingness to wear ridiculous capes, and the ability to pull it off?_ There was no denying the weight of knowing in Maximoff’s eyes, a serious answer to a flippant question.

“You believe that Loki was working with Thanos?” Her voice was low and intense—overtop, Sue barked orders; a half-dozen people teleported into the command centre in a burst of light, and four of them teleported away again; the others ran to terminals. Maximoff ignored them all, and Steve let himself ignore them as well.

 _“The timing’s too close to be coincidence,”_ said Tony. _“And New York got five times the number of attackers of any other major city. Loki was at Maklu, Thanos wasn’t—he had to have sold us out.”_

“We can’t win this in a straight fight, not without playing cards that should best be left out of the deck,” said Maximoff, tilting her head toward the gauntlet still lying on the table. “We have to take the fight to them. _Y_ _ou_ must take the fight to Loki. His involvement started on your world, with you—even now, I can see the way probability swirls around you.” Her eyes gleamed the same scarlet shade as her cape. “If you handicap Loki, then Thanos may—”

 _“What the hell do you think I’ve been trying to do?”_ Tony demanded. _“I can’t. Not with Thanos there to back him up. The pantheons tossed us out on our rear. Your own Gaea thinks that he’s an ally, she wouldn’t do anything. We have no allies.”_

“Have you looked to his enemies?”

_“Like who? Enemy of my enemy, fine, but he’s a god, his enemies will be, too—”_

“Duty is what keeps your allies away—duty to protect,” snapped Maximoff. “That’s why I’m here, talking to you rather than back defending my own world. But even in the face of annihilation someone with a sufficient grudge might be willing to help you end him first.”

“Everything we’ve seen has shown the pantheons united against Thanos—”

“Loki is a bastard— _someone will hate him more_.”

The intensity of her expression was enough to set off alarm bells in Steve’s brain—further alarm bells. There were already alarms ringing constantly throughout HQ—in the background, Sue was half-shouting at someone on the phone for moving too slowly. He thought it might be the President. Maximoff, however, was ignoring it all with a singular focus: she was dead certain of what she was saying, and it was the type of certainty that only came from experience. The burning look in her eyes left little doubt as to which side of that experience she’d been on.

 _“The dwarves,”_ said Tony, abruptly, voice clipped. Did he see it too? _“In the myths, they sewed his mouth shut.”_

The dwarf Loki had been working with had threatened something like that. Still... “He was working with one of them, when he grabbed me and Jane.”

_“Every country's got its quislings.”_

Maybe. But sewing somebody's mouth shut wasn’t killing. It was a sick thing to contemplate, but if they were looking for a villain to help them, then they needed one willing to murder. And speaking of turncoats... “Jotunheim. In our world he tried to destroy it with the bifrost.” Motive, and as for murder—the Jotuns had tried to conquer Earth in the distant past, when humanity would have stood no chance against them. They were villains, alright.

_“Their tech is a joke. Their world is a joke!”_

Right, Tony had been there—or its counterpart in the other cluster, at least. Would it be the same? Many things were similar enough, and something experienced was a better shot than something based on myth alone. But—“They were powerful enough to threaten Asgard, once. Maybe they’ll at least have ideas. They have to hate him.”

“Try it,” ordered Maximoff, with an authority that countenanced no disobedience. Her eyes shone like red stars, like hellfire and chaos. “Go, and swiftly. We will hold them off, but we cannot hold them off for long.” There was a crack and flash of scarlet, and she was gone to join the fight—whether on her world or 3490, Steve didn’t know.

Behind where she’d been, the display showed the truth of her words. Only a few blue points were left representing Udarnik’s fleet: the bulk of the others, ugly, sinister crimson, were breaking formation—to form a better perimeter for ground-level destruction; Steve could see it, suddenly, without needing the screen to put the rest of the details together. They were going to need the gauntlet, soon...

The best way in war was always to take the fight to your enemy, if for no other reason than to limit the civilian casualties that would occur when your enemy came to you. These were entire worlds; Steve couldn’t do a damn thing to defend whole Earths, and even with the Space Gem, if he was trying to fly under Thanos’ radar still, neither could Tony. “Tony. It’s either start using the Space Gem, or try it.”

Tony’s blank mask stared back at him. _“We need the full set,”_ he said, softly, over the comm. _“I can’t do it—not with the Space Gem alone, it’s, there’s too much to track. He’ll show up and—I'd need the Mind Gem. At least. But that won’t be enough power...”_

“Then Jotunheim,” Steve ordered.

Tony nodded. The world blinked.

The chaos of a world under siege vanished. Instead of the bright lights and alarms of the Baxter Building’s command centre, there was nothing overhead but stars, alien constellations and a galaxy like the Milky Way stretching across the deep velvet sky. Possibly it was the Milky Way—some alien variant of it. Mountains made of ice glowed brilliantly beneath the starscape, capturing the light and reflecting it so that it looked like they shone from within.

 _“Shit,”_ said Tony, and grabbed at Steve’s hands, just as the bone-wrenching cold began to register. Liquid metal raced over his skin, the warmth of it and the metallic smell combining to make it feel uncomfortably like blood. Steve breathed in, sharper than he’d meant to, and it was like breathing frozen fire. His lungs burned, aching, and blood ran over his face—no. Metal. A mask formed, cutting off sight—he could feel metal moving over the rest of him, not wholly covering his suit but forming protective lines of heat. He blinked, breathed in air that was thankfully warm, and the mask turned transparent. Steve tapped at it experimentally, with fingers covered in thin, metallic, _warm_ gloves, and it made a slight _plink_ ing noise.

 _“Jesus, I think this place is actually colder than the one I visited before,”_ Tony muttered through the comm in Steve’s ear.

“Which one is this, exactly?”

_“Jotunheim Prime. Didn’t see a point in bothering with lesser versions.”_

‘Lesser’ was an irritating term, but he otherwise had a point. Steve flexed his fingers, testing the gloves, and then rolled his arms, twisted his torso. The extremis moved with him, _almost_ seamlessly, but still... not quite. They were walking—teleporting—into territory held by gods of dubious moral fibre: he unslung his shield, tested a pair of punches and kicks, and managed a front-flip from standing. He couldn’t say he was _comfortable_ with the new restriction on his movement, but it was better than immediate frostbite. They didn’t have the time for him to work with it enough for him to learn all the ways it weighted in muscle memory.

The tilt of Tony’s helmet indicated some amusement when Steve straightened up from his landing. _“The major city’s a couple thousand klicks north. Ish.”_

Steve halted. “They’ve got satellites?” Tony had said they were primitive, for gods, but if he’d learned that much that quick, there had to be a system to hack. The Space Gem wasn’t much good for finding things, after all. That was the whole damn problem.

_“No, but they do have massive energy usage. Do you have any idea what you’re going to say?”_

“Haven’t really had time to write a speech.” He flexed his fingers one more time. More than anything else, he needed to know how his hands could move.

_“Then I hope you’re good at improv.”_

“Me? What about you?”

_“I’m hoping you’re good at improv.”_

The world blinked again, changing from glittering stars overhead and white ice all around them, to... glittering stars overhead and a black mountain glaring down.

There were also two ten-foot-tall giants, who jerked in shock at their sudden appearance, and then took careful steps back into a fighting position. Spears of ice formed in their hands, razor-sharp.

“Halt,” snarled the one on the left.

 _Bully,_ something inside Steve sized up.

Steve held up his hands—not exactly peacefully. “We’re allies,” he growled back.

“Mortals,” sneered the other one. A thicker line of frost raced over the rime-coated ground and crawled up a wall and out of sight—it wasn’t all ice, here; there was stone mixed in. For all their sneers, both guards continued to eye him and Tony warily, not relaxing. They were better at their jobs than most bully guards tended to be, then.

Steve flicked his eyes to the side, trying to take in more of their surroundings without looking as if he was doing exactly that. The jagged mountain above them seemed natural enough in its formation—but out of its face massive pillars had been carved, the basis of a palace designed for someone who dwarfed even the giant guards. Other structures stretched out around them—“Tony,” said Steve, quietly enough that he hoped the guards wouldn’t hear. He _was_ wearing a mask, after all... “Did you drop us in the middle of their capital city?”

 _“I’m starting to think I should have dropped us in the throne room, but there’s nobody in there at the moment,”_ said Tony. _“I’m also thinking I might have, um, underestimated their tech level.”_

That could either be good or very, very bad. “Oh?”

_“Fucking alien cities.”_

That was not illuminating. Before Steve could point this out, the line of frost that the one guard had made redoubled, puffs of snow bursting from it and curling up in the light wind. Both guards scowled simultaneously.

“You will come,” said the first, managing to make it sound like a threat. The spear of ice lowered... it was hard to tell if that was also a threat, since it was now nearer the level of Steve’s torso, or if that was just the height difference. “Queen Laufey will deal with you.”

That was definitely a threat.

The guard slapped his hand to the wall; ice groaned and stone shrieked. The black gates loomed open.

Ice running along his spine, Steve stepped through with Tony at his side.

 

* * *

 

 _Earlier,_ Tony told the Time Gem, and it obeyed.

He skipped past events at even greater speed—acceleration, second per second—this time, not trying to look too close at chasms that made his brain ache. Maklu rose and fell. Possibilities boiled away, things that _might_ be and he wasn't sure _had_ been. The Time Gem had some sort of ability to support paradoxes, he _knew_ that, but his brain didn't, or maybe his first instinct had been right: there was something wrong. He could see both point and transform and the flaws therein, things overlapping where they shouldn’t, aliasing. Ten hundred thousand timelines tried to stack themselves up in his brain and he flung himself back further, only a dim thought in the back of the head ensuring that his body stayed back on that alien world, that he didn't take it along for the ride. Extremis faulted and he dumped data off the buffer, thought _earlier_ again and again, until the Time Gem slingshot him into a _greater_ awareness: six points of power coming together in unison, toward a point where the Time Gem had been joined together with the others, the whole and complete set of Infinity. Around them, the Gap drew close, all of Reality's superstructures collapsing and shrinking down.

STOP!

He hung in a frozen moment. Ahead of him, energy fluxed, a meteoric rise ahead—something that could dwarf any reality, all realities.

_Avoid system-failures. Also the attention of gods. And the Big Bang._

There were six Gems here, morphing out of what had been a whole. He didn't need to go back further to find them: he reached for them with Time and Space.

Then hesitated again. To change things _here_ , at the origin point, would change— _everything_.

_Everything._

He could solve all of it.

...If he could manage it. Someone caught in a time loop had tried to rip away the Time Gem from him just now, and he'd resisted it, yanked back in a way that might have caused one of those cracks in the universe—and that had been when he'd been half-crazy and drifting. If he tried to change something here, how much resistance would he have to overcome?

Besides, he understood barely a fraction what he'd just seen looking backwards through time on fast-reverse. What were the odds he'd accidentally remove the Earth from existence?

_Think, idiot. Go later, see how it falls out._

He examined the pieces, first. The Time and Space Gems were easy to spot; he knew what they were and how they worked. Figuring out the others took more effort; he re-watched their approach to/from that beginning, backwards and forwards, and it occurred to him after the third time that the itchy feeling in his skull was from the close proximity of other observers: himselves.

The Gems were complementary: they worked as a set. In short order, he identified the backbone of control, the brain: two pieces. One for software, one for hardware? He wasn't sure. The green one he identified as the Soul Gem, based on Steve's description, but the other one was what interested him—it had the _structure_. Link up to it, and he was pretty sure he'd have enough processing power to figure out the solution to life, the universe, and everything.

He focused on it, and watched a blue point of light fall into the hands of a race of primordial gods—perhaps one generation removed from the Elder Gods themselves. Prepared by his experiences going backwards through the Time Gem's history, this time he watched on fast-forward. The highest among them claimed it, creating an empire across the realms, then lost it, to stupidity, to treachery, to naivete, to fear, through a long line of owners; most of them he never saw, skipping past their experiences in the space between one moment and the next. The chain continued, and that was all he cared about, watching until the Gem fell into the possession of one tiny cult, which sequestered it away near the borders of unreality... until, for a moment, there was Steve and Jane, discussing it and calling it the Mind Gem, and if Tony had still had eyes, they would have widened.

But Steve, too, lost it in turn.

He watched Steve say the mantra, and it didn't affect him. It had already found its mark.

Grief and an irrational feeling of betrayal broke his concentration, and his mind snapped back to the present.

* * *

 

There was no ‘might have’ about it. _I way under-estimated their tech level. What the hell_ is _this stuff?_

Signals bounced along the ice palace's walls, _in_ the walls, faster than even extremis could track. Their guards weren’t making use of it that he could tell; it was limited in some fashion, if only because there _had_ to be a catch to anything this good. He let nanites drop off of his boots as they walked-slash-jumped up a staircase made for giant feet—Steve took the steps easily, and this time around, Tony could, too. The nanites clung to the ground, and through them, he dropped tentative signals into the stream... which vanished, ripped away. He pinged the nanites, then sought them out with the Space Gem, and found that they’d been reduced to dust.

_Shit._

It wasn’t like Asgardian tech. It also wasn’t like Makluan tech, which wasn’t like Asgardian tech either. If he had to start all over again, learning the basics of a third civilization’s tech before he could understand the advanced shit— _No. There isn’t time._ Worlds near their own were under siege, and it wouldn’t be long before Thanos, or Loki, came after the Space Gem. After that... with three Prime Infinity Gems in his hand, how long would it be before Loki gained the rest?

From the mountains looming above, there was a sound like stone crumbling, or an avalanche. It echoed through halls made desolate by age and decay. The edges of ice and stone were no longer razor-sharp by design; those icicles that grew blades did so as if by accident. The place was one step from becoming a mausoleum. But _why_ , with the power that coursed through the icy walls?

Laufey’s throne, twelve feet tall and raised on a dais that was crumbling about the edges, was as run-down as the rest of the place. The queen herself was not. Ice clung to her, glittering patterns that fractured and spiralled into ever-smaller fractals—an array of icy colour that, seen by human eyes, was simply white, but became so much more when the hundreds of wavelengths were viewed individually: patterns that started large in the infra-red, as inexact as it was, and became more exact the bluer the shift...

Tony was no stranger to fashion designed to impress, but short of the Iron Man suit, this might have been the first time he was genuinely _impressed_.

As they approached she lifted an idle finger; the guard in front of them went to one knee and bowed his head. “My queen. The visitors, as it pleases you.” He even managed to sound completely sincere about it, despite having growled at them earlier like he wanted to put an ice-pick through their heads.

“You may leave Us,” said Laufey. The finger dropped back to the arm-rest. The guard climbed to his feet and walked out, apparently without the slightest care that he was leaving his beloved queen alone with mortals. Was that because they were mortal, or because she’d been the one to build that dress? Or—“You may all leave Us,” Laufey said, and a dozen pillars of ice detached themselves from crumbling walls and walked toward the doors, movement revealing giant limbs.

_Fuck!_

His scans had missed the hidden Jotuns—this was something better than his tech, something like Sue’s ability to vanish utterly. _Damn it._ The doors closed, and they were alone.

Probably.

_I can leave any damn time I want, stop freaking out._

“Queen Laufey,” said Steve, stepping forward and actually offering her a bow—although not, Tony noted, one deep enough that he had to take his eyes off of her face. “Thank you for seeing us. We’ve come to ask for your help.”

“You are here because you are in possession of a powerful weapon,” Laufey corrected. Her eyes were as dark and fathomless as the frozen ocean. “Name your price.”

The Space Gem. _Shit._ Tony checked his precautions— _how had she picked it up?_ His own damn carelessness? If she could _see_ in the same way Thanos was supposed to be able to, mind spread wide—

Then they definitely needed her help.

Steve hesitated, not that anyone who didn’t know him—and didn’t have a nanoenhancile mesh next to his skin, or maybe who didn’t have Natasha’s level of training—would know. “It’s not for sale,” he said determinedly, and went right on, like a bulldozer, as Laufey drew in breath and a wind swept the hall. “If we _give_ it to anyone, it’ll be as a gift, and to an ally.”

“We are all allies against Thanos,” hissed Laufey, but the force of her rage, so briefly felt, had been diverted.

“Is Loki?” Steve asked, his chin up, feet planted—a bright, bold spot of light on an infrared spectrum that showed mostly in shades of black.

“Do not,” said Laufey, rising from her throne—“speak _that name”—_ information rose, the noise leaking over from the signals in the walls spiking exponentially— _“in the halls OF MY PALACE!”_

Her shout was just noise; it was nothing compared to that from the walls. This was the last river before Maklu, emptied; this was the nanites of that vast waterway, stripped of their duties and carrying nothing except silence. Tony teetered on the brink—he could barely sense it, everything setting and resetting so fast he couldn’t keep up—it was a supercomputer. The palace, hell, the entire city was one giant supercomputer. _Supercryo tech, kept at temperatures barely above zero K — holy shit._ If he could just _control_ it—he yearned to dive into it... which would fry him just as badly as the nanites he’d tried it with. This was so much _bigger_ than anything he had with him.

 _“You live in a supercomputer. You live_ in _a—how the hell did you lose to Asgard?”_ he demanded, and, fuck, if he’d had his brain sucked into the walls then maybe he still would have been too slow to realize that was a really dumb question to ask. _Way to go, Stark._

Laufey turned to look at him, her movements as slow and unstoppable as an ancient glacier, ready to roll right over him. But he had to know. She obviously had _some_ ability to control it, at least in part—the data flux during her display of temper was telling, and now as her fury crystallized, frozen solid, the roar died away again. But if she had full access to it, she wouldn’t be speaking to them. This palace wouldn’t be a half-abandoned ruin.

“We lost... because we were betrayed,” she said at last. Her words could have cut like a knife, each tone was so sharp. “Not in battle, but a generation before. We lost when my father sealed away the Casket’s Key, and with it all knowledge of our true power.”

 _Right. And you just never rebuilt, in a couple thousand years._ Or maybe he was being too skeptical; maybe they’d tried, and gotten smacked by Asgard for it.

“But you come here now, possessing a mighty weapon,” Laufey continued, and then her gaze knifed towards Steve. “And you _burn_. Bright. This is Our bargain, mortals: we will grant you aid against that runtling upstart, and in return, you will use your weapon to return Ours to _Us_.”

_“Deal.”_

“Tony—”

 _“This is it, Steve,”_ Tony told him, comm only. _“This is what I need—what we need. It’s a supercomputer. To work out how to get access for her I’ll have to get access to it myself, I think—I_ know _—it’s big enough, I can feel it in the walls.”_

“You’re really not making much sense here,” Steve muttered, and he didn’t have to add, _which isn’t helping convince me any._

 _“It’s a supercomputer big enough that if I connected to it... I could spread my brain across the whole damn universe,”_ he said, and saying it aloud—not in the primitive, human way, but rather whispering it across radio frequencies... such a cliché: but here, in this place, it made him shiver. _“There’s three Gems left up for grabs out there, and I’ll be able to find them.”_

“Using the Gem will get Thanos’ attention—”

 _“And if I get Loki first, then I’ve got four Gems, maybe all of them. With that... with that I can do something. Steve, this is_ it _.”_

“Tony, you’re making it sound so damn easy—you got lost in the damn internet!”

He had.

It would be so easy to lean toward that ceaseless stream of data and let the overload take him. If there was a Key, some way to control it—but there was guarantee it was anywhere near that straightforward.

_“And maybe I’ll get lost again. Or maybe not. There’s three Earths out there dying right now—”_

“Yeah, so we better make it _count._ ”

It was the Window all over again, a chance he _knew_ instinctively would work, but Steve wasn’t going to—

_But I was wrong about the Window._

The thought brought him up short. He’d never run the numbers on the Window. There hadn’t been enough data to run numbers _with_. He’d _wanted_ it to work, but that brief grip on the Time Gem had told him that no, it never would have...

But this wasn’t the same. There was no Tripitaka here, telling him it wouldn’t work. No one here to _defy._ This was his own judgment call to make—he just had to make it. Steve was a commander; Steve wanted the odds. _“Alright. Alright, let me think.”_

Think, and analyze. Data from usage of the library nexus in Maklu scrolled past his attention, and he compared it to the flashing, supralight signals he could barely read from the walls around them. It wasn’t much the same, but how different were the denizens of Jotunheim from the citizens of Maklu? In the end their awareness had to be similar level—if they were beyond it, they wouldn’t have been so easily crushed. And hadn’t Gaea said it? There were the Elder gods, and then there were those below them.

Jotunheim’s supercomputer was vast, but it wasn’t the same reality-breaking power that the Elder Gods had displayed. It could spread his brain across the multiverse, but it was a poor substitute for the Mind Gem.

_“I got lost in the Internet because I thought I was dead to start with, and frankly the Internet’s not designed to be interacted with that way—it’s too primitive. I did fine with the library nexus in Maklu, and this isn’t all that different, except in scale. If it comes down to it I’ll partition off the part of my brain working on it, but I’d give four-to-one odds against that being necessary.”_

“Tony...”

 _“Those odds are worth it and you know it. The Space Gem isn’t doing us any good so long as we’re unable to use it against Thanos, which we can’t without the other Gems that we don’t have. So, while I could maybe save lives if I go back and don’t try this, in the end it will be a war of attrition and we will all die. But this I can try. This is worth risking my life for,_ and _worth risking the Gem for, and—this isn’t the Window of Time. This isn’t me trying to play god. Steve. Please._ Trust _me.”_

Steve stared at him, half in horror, and Tony realized that he was sounding too desperate. He was begging. _I will get down on my knees in about three seconds if he doesn’t say —_

Steve looked at him like he was trying to stare through the faceplate. And... okay. Tony could give him that. He let the nanites shift, turning the ones in his helmet transparent. No doubt his hair looked terrible—but whatever Steve saw he approved. Didn’t like it, but approved.

_Hell. Not a soldier. Maybe close enough._

“Alright,” said Steve. “Alright.” He turned to Laufey. “You have a deal.”

Laufey’s chin jerked up: a sharp parody of a nod, made majestic by her stature and bearing. She descended the steps of her dais and strode toward them—they parted, one to each side, and Tony had to toggle off the combat algorithms that tried to auto-run. She strode toward the doors, and when she was halfway down the hall, she raised one hand.

A blast of air, so cold it momentarily shorted out his temperature readings—the fury of a thousand deep winters—froze the doors solid, metres of ice forming in an instant. Betrayal? But there was something stirring in the ice... it cracked, one jagged break right down the centre as Laufey dropped her hand, and chunks the size of a small car broke away, tumbling to the floor. Laufey flicked her hands out to either side and the ice boulders were hurled away to smash into the walls and pillars. One pillar collapsed beneath the weight—fortunately, it wasn’t load-bearing. It toppled outward, its impact with the nearest wall and the floor only adding to the cacophony.

The last of the ice crumbled away, flash-freezing so deeply it disintegrated, and the doors had changed. They were still carved from black ice—still two smooth sheets. More ice had frozen over between the crack, sealing them shut. Where the handles would have been, right in the centre, was an indentation, a half-sphere about a metre in diameter, like someone had carved a scoop out of the doors—which, incidentally, had to be at least half a metre thick, because the indentation didn’t break through to the other side.

Tony let the Space Gem take his mind past the doors, and found only the emptiness of the Gap beyond.

_Her dad tossed it into the Void?_

No. _That_ was too simple.

Within the indentation burned a... not exactly a black hole. He wasn’t quite sure what it was. It burned like frost did, water so cold that nerve endings became confused. The Space Gem did not let him grasp any part of it. It radiated nothing. A perfect ball, maybe the size of his fist... _and as far as I can tell..._ actually _at zero K._

Runes were carved along the bottom of the indentation. They were messy and faint, like some idiot had taken out a pocket-knife and done a half-assed job carving their initials into a tree. Tony had no idea what they said.

Part of his mind flickered back Earth—their Earth, yet unthreatened by a ship hanging in the sky above—and began to search through data-bases, but there was nothing like this. A wholly alien language, one that had never touched Earth?

“It reads, ‘Mystery is fire. Truth burns,’” said Laufey. She shifted her stance ever-so-slightly, not exactly beckoning them forward, but it no longer felt like they were _forbidden_ from coming any closer.

 _“And that’s... it,”_ Tony said aloud—just to confirm it. _Okay. Not what I was expecting._ _“That’s the key.”_

“I am the Queen of Jotunheim, and all that is frozen is my domain,” said Laufey. “But even I cannot touch that which has absolute stillness, cannot freeze or thaw it. No one ever has except my father—and doing so killed him.”

_Then I’m right. Absolute zero._

There had to be a catch. There always was, with this type of thing. The key was to figure it out before the poisoned needle pricked his finger. Tony reached out again, slowly, with the awareness that was half him and mostly the Space Gem—adding up to something greater than one. A millimetre from the surface of the Key, his sense of the Space Gem shuddered. No, not space. The key was—not a _gap_ in space—his mind struggled to find a way to make sense of it. A breakdown in physics, like the Window but also not: the Window had still had some heat left behind it. It could be passed through to the other side of the break, revealing the Gap beyond. This was... not just a sphere, ten centimetres across; it was a single _point_ , frozen, somehow given three-dimensional form. A bit of broken reality.

How the hell had anyone, even a god’s father, managed to freeze reality as it broke? Kuan-Yin had had no damn idea how the Window had formed, and she’d had the full knowledge of Maklu at her disposal—but Gems weren’t shattered every day. Then again, if Jotunheim had had _this_ supercomputer, at some time in a distant past—

_The Time Gem shattered — shatters — and makes the Window. If another shattered..._

If that was it, that still told him nothing about how to break or bypass the damn thing, short of inviting Thanos for tea.

“Well?” asked Laufey.

 _“Let me_ think! _”_ he snapped at her.

The corners of her mouth rose into a cruel slash of a smile. “But of course, mortal. _I_ yet have time.”

 _Ignore her, ignore her —_ she was standing as still as a statue, it _shouldn’t be hard to do, right?_

 _“Who carved the runes?”_ he asked, which wasn’t exactly ignoring, but was relevant.

“My father. As he died.”

_Explains the shitty penmanship._

“Tony...” said Steve, softly, and Tony toggled the nanites in his mask, switching them to mask audio.

 _“Private comm link,”_ he told Steve. _“Okay. This is definitely it. I don’t know what her dad was into, but this is like the Window. This is something_ wrong _in the fundamentals of the universe, a break-point.”_

“What’s the catch?” Steve asked, because he wasn’t an idiot. That, or he was being insulting. But it was a fair enough question, considering Tony hadn’t already grabbed the Key.

_“It’s frozen so cold that going near it with the Space Gem makes the Gem start freezing, too.”_

“That sounds very cold.” There was a note of distaste in Steve's voice.

 _“Yeah.”_ Actually... Tony extended his awareness again, not quite poking it. Then he stuck his hand out, this time not focusing on the behaviour of the air, but of the nanites themselves. _“Huh. It's making the stuff_ near _it act like substances at negative temperatures. Huh.”_

“I'm assuming you're not talking about Fahrenheit.”

_“Good lord, no. Kelvin, the scale of all good little physicists. Negative temperatures happen when you run out of states to put energy quanta in—which means the only place for them to go is away. So negative Kelvin works out to be hotter than infinitely positive temperatures—temperature's a closed loop, with an asymptote at zero. But that only holds so long as it's one quanta per state. And guess what Bruce disproved using the Euclid Paradox?”_

“Something about quanta?”

_“Bingo. So it's pulling in energy without getting any hotter. At a guess, whatever the break-point is, it's absolute zero. It's pulling in energy and just sticking it all in the same place, freezing it.”_

“If it's pulling in energy,” Steve said slowly, “without getting hotter... how do we thaw it?”

_“That would be the catch.”_

Steve let out a breath that wasn’t _quite_ a groan. “Mysteries are fire, truth burns. Right.”

_“And apparently you burn bright, too. Come on.”_

They stepped past Laufey and toward the doors. She really _could_ have been a statue; she didn’t even breathe. Three metres from the Key, it was like they’d passed an invisible line; the air temperature dropped from low triple-digits to just this side of liquefying— 84K, which was positively toasty compared to the single-digit temperatures he was reading from the floor. How that temperature gradient was being maintained was... possibly important. He couldn’t measure it directly—if the nanites touched the floor without the insulating bubble of heat he was having them throw off, they’d shatter. He put one hand on Steve’s shoulder and pulled more nanites from his subspace stores, tossing them over him. Wire heating wasn’t good enough here.

“Tony?”

_“Just in case.”_

“If you say so.” Steve grimaced. “Okay. This is a puzzle, right? We just need to think it through.”

_“A puzzle that’s stumped an entire civilization for at least two generations.”_

“I have confidence in you.”

_“Thanks so much.”_

“Uh-huh,” said Steve gamely. “Okay. Mysteries are fire, truth burns... fire burns—mysteries are truth?”

_“If you want to be literal about a metaphor, actually, burning is the reaction and fire—heat and light—is the by-product.”_

“Truth burns—reacts—and produces mysteries.” Steve shifted back on the balls of his feet—in balance, always in balance; the man was the paragon of physicality... but, stance now contemplative rather than aggressive or defensive. “Okay. Tell me about the Space Gem.”

_“What?”_

“Two generations couldn’t get through this, but Laufey thinks you can, because you have the Space Gem.”

_“Yeah, well, she might be wrong. It can’t touch this. I tried, but it kind of slides around the edges. An asymptote.”_ _A point..._

“Wait, do you mean—is it also a Gem?”

 _Perceptive._ _“I don’t think so. The Time and Space Gems aren’t points—well, they are, but they’re also simultaneously not. I think. They’re themselves and also their transform simultaneously, both in Reality and in the Gap—that's not weird, but they're their transform_ in the same space _, and that's weird._ _”_

“Their transform?”

_“Their representation in—a different type way of looking at things, did you even take calculus back in the thirties?”_

“High school, sure. Can’t say I remember anything about transforms, but keep talking anyway.”

Tony snorted. _“Fine. A time gem broke in Maklu, and I think it might have been_ the _Time Gem. I think Toni managed to grab the Prime one before it broke. I think that created the Window—I mean, it broke part of the_ concept _of Time, and it created a flaw. You can’t just do that in reality—things go wonky around the edges. Like—okay, for example: the invisibility cloak. The easiest part of it is the middle, it’s making the edges line up that’s a pain in the ass. So the Time Gem broke, and the Window formed around it—a roughness at the edge of reality, you could say. Because when the Gem broke, it stopped being both things at once... kind of like this...”_

“Thanos being around cracked the Window.”

_“Thanos and the Living Tribunal going at it, I think. Shattered the flaw again, and that made it possible to use the Space Gem to reassemble the Time Gem from its pieces. Or it might have been that causality was going backwards at that point, and me putting it back together caused it to look like it was shattering from our point of view, er, at the time. Or maybe I could have used the Space Gem to grab the Time Gem from the Window all along, if I’d had it then. Without the Time Gem, it’s hard to say.”_

Steve snorted. Tony looked at him, inviting comment, but Steve dismissed it with a shake of his head, and instead said, “But you can’t pick out the pieces of whatever-this-is here.”

_“No.”_

They both stared at the point for a few minutes more. Tony ran backwards and forwards over equations, double proofs that couldn’t both be correct, trying to get them to line up at a point—and all of it was so _slow_ , compared to what he’d be able to do if only he could solve this and get access to the supercomputer in the walls.

“Maybe it’s not a puzzle,” said Steve quietly. “Maybe it’s just a statement. Truth creates mystery. History obscures.”

The Time Gem could shed light on any truth lost to time—but they didn’t have the Time Gem. He’d lost it. He had the Space Gem, and this _whatever-it-was_ , mocking him. If he _forced_ the Space Gem to touch the frozen surface, binding all the Gem's energy into it, would the Space Gem shatter, too? Leaving them with two broken Gems. _Truth, understanding... Mind or Soul Gem, if I had to guess, but one of those definitely isn’t broken. Unless Laufey’s dad went in for Nietzsche — if so, could be Power. Or Reality, which isn’t broken either._

_Is it?_

A point and an infinity. Two truths that shouldn’t both exist at once. Broken, and unbroken—and did it _matter_ when it broke, if it could be both at once? Run the puzzle backwards; mystery and truth became the same thing. _It doesn’t make any sense._

It didn’t make sense.

And it did make sense, in the same way of all the other impossible pairings, because it was no greater an impossibility than the Euclid Paradox.

The Key was a point that he couldn’t grasp, but he stepped forward anyway, holding out his hand with the bright light of the Space Gem shining around it. Metal creaked, froze to ash, and held, because the Gem was a point as well, two points meeting and overlapping but still _unique_. The Space Gem was cracking and shattering and reforming: the infinite reach of the Gem was the transform of the absolute motionlessness of the Casket's Key, both present at once because—

 _“Something’s wrong. The universe. It’s—broken,”_ said Tony, and then his mind—

—slipped—

S

I

D

E

W

A

Y

S

—and the Gem narrowed to a point. The Key was a single point that _was_ the computer running through Jotunheim, a single point that _wasn’t_ , the rules of reality and Space breaking like the Space Gem in his fist, shattering now just like it had shattered—would shatter—a wound on reality that didn’t care for causality, that ran backward and forward just like the Window of Time could reach across Space. The Space Gem was whole and broken at once, and it was in that duality that the Jotunheim supercomputer existed.

The additional memory was one giant leap, a non-differentiable function, approaching zero one moment and nearing one the next; his mind didn’t sprawl out as it had through the library nexus, but gained the entire thing at once, an infinity contained inside a point. And this was approximate enough to infinity, a boundless reservoir compared to the teaspoon of the library nexus, enough space that when he looked outward, the Key let him see _everything:_ it gave him a mind wide enough to see all of Reality at once. His awareness filled the Cluster, as dense on reality as the rational numbers in the real number line, no space too small to crawl into.

This was the awareness of God.

And another being with a Presence that filled Reality, and broke Reality, saw him, and looked back... with all the Power of the combined multiverses at its disposal.

 

* * *

 

Tony lost control of the Time and Space Gems' awareness and found himself back in his body, back on an alien planet, about to be sick.

Protocols rewritten on the fly cut that off before he could retch. He melted the faceplate away, breathed in fresh air that tasted like ash, and tried to ignore the phantom taste of bile at the back of his throat. If he tried to grab the Mind Gem—would that take him too close to Loki? He didn't dare follow the Mind Gem further, once Loki had it. The slightest chance that Loki would somehow detect his awareness floating around out here was too much— _Loki had the mantra_.

Loki had made Steve use it.

No: he couldn't go near. He had to grab it _before_ Loki got his hands on it. It had existed for eternities floating near to the Gap. Tony had been able to pull back against the Space Gem, but the Time Gem angled in from a different direction. He let more of himself flicker between two times and places, enough that he could reach out and—

It was like trying to yank a burning brand, a mountain of iron, a pillar of the world. Nothing budged; his hand went right through it and ten hundred thousand timelines burst in his head, dying before they could be formed, and this time when he fell back into himself he was screaming and it took him a while to stop.

_STOP IT, STOP IT, STOP IT!_

The shock of it crowded out his mind. When he could think again, all his thoughts were repeating in a loop, thankful-as-christ: that hadn't been Loki yanking back, that had been reality collapsing in his head, _thank god thank fucking god._

Okay. He was okay, he was safe, he was okay. Loki wasn't coming for him, Loki hadn't seen him.

He hadn't.

Even if he had, Loki didn't need to bother. Whenever he wanted to punish Tony, he could do so at his leisure.

Tony threw off the helmet and let the bulk of the armour crash into the dirt. Ash. Whatever. Flakes of it curled up and around him as he paced back and forth, watching another sun rise over a distant horizon. Clouds gathered overhead, more ash than water vapour, obscuring the nearer two suns.

 _He didn't see me, it never got that far._ No matter how close it had been. He repeated that to himself until he could think.

So. The Time Gem had limits to what it could rewrite: that... made sense. One of the other Gems he'd seen splitting off at the beginning of Time had been _blistering_ with power, no clear point to it except as a battery for the other five. It made sense that without that one, there were limits, and as limits went, stealing other Gems made a certain amount of sense, considering they were—what? Cornerstones of Reality?

He was going to go nuts if he tried to get into philosophy right now.

Being unable to steal them from far back in history didn't mean that this wasn't still an option. He could use history to track down where they were, steal them in the future. The Mind Gem had been unclaimed until only recently, after all. If any of the others were...

He needed to get his hands on that Power Gem. If he could just get that one, he could change—everything.

_Hold the horses. Jesus._

Changing everything was too tempting. He needed to figure out what the others did, first, what their history was.

He needed to know what he was doing before he kicked off another timeloop that got even more people killed.

Tony balled his hands into fists, one Gem at the centre of each. Back to the beginning, and this time he followed the yellow point of light—across multiverses, across wars and chaos, across the reshaping of Reality. In the shadow of its light the structures visible from the Gap were thrown into sharp relief: nodes in the frequencies that the Time and Space Gems allowed him to see, to understand. He saw fractures in those substructures, spindly, _wrong_ things, but just before their origin could be revealed he saw himself, again, and Steve, and Maklu broken around them, too close to the Time Gem breaking, as Loki, laughing, claimed another Gem—as timelines overlapped, and a woman that didn't exist tried to yank at the Time Gem that had existed in some of those pasts, and the whole thing collapsed as the datafront did its best to fry his brain—

He rebooted again, and this time bile tasted like despair. That hadn't been his past self, that time. Oh, it had happened in the past, and it had been his version of the Time Gem they'd been attempting to steal, but the Tony Stark standing with Steve Rogers hadn't been _him,_ and none of that had ever happened to him, which meant that unless there was something seriously wonky going on with the timeline, it must have been his future self. Would be his future self.

Unless he changed it.

Tony went back to the beginning again.

Green—the colour of souls—and Tony followed it through another bloody history. But the Soul Gem was different: it _knew_ he was there and hated the abomination of him, a thing without a soul. Tracking it gave him a headache, one that grew worse as the Soul Gem grew angrier, and when it fell into the hands of a primordial demi-god that used it to reap the souls of fallen ancient aliens, he wondered if it would have enjoyed the act so much if not for him.

But the Time Gem didn't have enough power to do that, if it couldn't rip away the Mind Gem. Did it? Or was this some kind of time loop? He didn't know enough.

He kept watching. The Soul Gem passed through the hands of gods, monsters, and demons, was won and lost by sorcerers and adventurers, spent several eons in a crypt, spent more eons being handed around as a trophy. Tony watched in a daze, keeping his distance as much as possible, until, very suddenly, it ended up in the hands of a Steve Rogers.

A Steve Rogers who went to Maklu, with Anthony Stark, to see the Chief Magistrate.

_Steve..._

If he could have pulled Steve away in that instant, into the safety of the future, then he would have. But Steve had uncovered the Mind Gem, and the Time Gem didn't have the power to alter the course of the other Gems. Probably. Unless something else had been going on.

_See where this goes first. I don't know enough yet._

“Is it fate, that as the end of days approaches, this turns up now?” the Chief Magistrate asked aloud when she had sent her two human guests away. She examined the Soul Gem for a while, then took it down to vaults to be guarded by the most trusted of the Magistrati... but when the vault was shut, a figure detached itself from the shadow beside the door: a figure wearing a horned helmet, with a mad gleam in his eyes. Tony shrank away, despairing, as he watched Loki's fist close around the recalcitrant Gem.

Before he could break his concentration and retreat, the world changed, as Loki portalled away and brought the Soul Gem with him. This new place was familiar, a mess of broken buildings. Familiar enough that Tony froze, motionless while the scene played out.

He could have lived a thousand lifetimes without seeing this place again.

Mere months ago he'd woken up here in a newly rebuilt body. Extremis had healed injuries that should have been crippling, and he'd opened his eyes to find himself in a wasteland of death.

This was days or weeks before that, and while it was still a wasteland, right now his past self was just one of the many ruined things in it. Loki stood over a body that was broken and wasted, a husk whose mind had largely wandered off into the far corners of the world—a husk that couldn't die, thanks to the curse that lay upon it. A husk that hadn't gone insane, thanks to the injection of pure, properly configured alien nanites that he'd had forced upon him.

Tony watched in bleak disbelief as Loki raised the Soul Gem and ripped away his past self's soul. The Gem sang with exultation that Tony could feel pulling at an empty place within himself, the place where his soul _should_ have been, while Loki's eyes glittered with an equally mad triumph...

Below Loki, Tony's body twitched. Loki looked down at it, laughed, and vanished, dragging Tony with him again—

Tony let his focus go, and snapped back to the present to find himself doubled over, one hand pressed against the arc reactor. The desolation of the alien world enfolded him, and he fell to his knees. He'd never before noticed the hollow place where his soul should have been, but now it _hurt_.

_You goddamned bastard._

Maybe the bastard just wanted it as a trophy. Maybe to gloat. Maybe it was the Soul Gem prompting him, having been frustrated by the soulless presence following it throughout history—maybe Tony had brought this on himself. Or maybe there was another reason, because Tony didn't trust Loki as far as he could throw him.

He swallowed, and pushed himself back to his feet. _Later. Figure it out later._

There was one last Gem out there, the most important of all: if he could secure the Power Gem, he might be able to grab the others. It wasn't much of a hope, not when Loki had claimed the others so skillfully, but he went back and began to follow its history—

—and nearly tripped into the colossal _Presence_ that claimed that last, blood-red Gem, pulsing with the Power of the cosmos—claimed by a hand that could wield it freely, wield it with laughter at the slaughter. The Mad Titan _noticed_ him, for one awful moment, and then Tony fled. Discorporate, timeless, sustained only by twin points of light, Tony fled, not into the future, but to anywhere—an alternate shape, an alternate viewpoint, an alternate method of _looking_ at reality, while malevolence roiled up between all the cracks in creation, all the flaws where Time and Space split—

—split like the inside of his head, as ten trillion states flipped into faults back in corporeal space and time—

—error states mirrored in the cracks running through and across the breadth of Reality, cracks that he could see from a point of view scattered far beyond the finite atoms comprising his brain—

—confused, inside-out, upside-down, everything twisted around, and all he could see were the lights of the Gems, and the glowing patterns of faults in Reality. Time and Space transformed, standing still, presented in forms that were outside of them both. The pattern was clearly illuminated by the fire of two infinite points. The origin of the fault in Reality: and all the forces working, that had worked, that would work to reforge it _better—_

—and at the same time he was screaming without air and without end, because the pain had lit up his mind like a supernova, and he fell back into himself to scream with corporeal lungs—


	19. Mind and Matter: 4.4

The superluminal processes of the Jotunheim Key let Tony’s mind roll across the universe with close attention to detail—more than enough to catch the way the Power Gem shone in Thanos’ grasp. And nearer to him, scattered across copies of Jotunheim, three more bright, burning points: Reality, Mind, and Soul. The Time Gem flashed across his consciousness and was gone before any other details could be discovered; _someone_ had it, and they had vanished with it, taking it to another time. The Space Gem disintegrated in his grasp, breaking—or repairing into the Key, in reverse: locking it shut, the moment gone, ripped apart by the flaw that ran throughout all Reality, not just this jagged dimensionless point.

And then time ran backward, and the Space Gem was just a point once more. It dropped, and he couldn’t see where it fell.

The disconnection from the Key left him reeling, half-stunned. The all-knowing awareness wasn’t even a memory that his extremis-enhanced mind could properly remember—it was mostly junk data, little bits of a bigger picture that didn’t make sense on their own, every 1040 HD picture reduced to a pixel. But he knew, he _knew—_

He, stumbled, fell, and strong arms caught him. “Easy, I have you,” said Steve, and there was no time to contradict him. Tony wrapped them in subspace and forced the portal device in his armour to flare to life in half the time it should have taken and—

_Stop,_ said a familiar, hated voice in his head, and he did. His subspace bubble burst without a pop, and realspace settled back about them.

“Tony,” said Steve, setting him down carefully, “Tony? Please, God—”

“Did you find it?” demanded Laufey— _not_ Laufey, she had _never_ been Laufey—suddenly there: no, there all along, because there was the Space Gem’s amethyst light gleaming from her palm. She was the one who’d grabbed it, unseen. And there were the other three lights he’d seen in her hand. Tony could feel her digging into his mind, pulling secrets inside out, the memory of the Space Gem falling to pieces and the bare knowledge of what he’d found beyond, the few things he’d saved to extremis. Other secrets—things Loki might have already known, but which now she _definitely_ knew—doomsday weapons, the Nullifier, his every half-formed hope of removing the Makluan headband, making pain claw across his mind.

“No,” breathed Loki. There might have been a tiny hint of despair in it, but then it was gone. “So he has had it all along. Well, then. Four shall have to suffice.”

And then Loki's thoughts weren't the only pressure raking at him. A Presence had arrived, vast and terrible.

But not shatteringly so. They were wrapped up in the smothering presence of four Infinity Gems, and Tony saw the moment that Steve froze above him—saw the helpless rage in his eyes as Loki drawled, “Stop, Steve.”

He could see. He could think. But he couldn’t _do_ one damn thing, send one damn command to the armour. Loki paced nearer, and her form rippled—no illusion, that: some sort of shape-change. She was giant-size still, female still, but there was no mistaking those features, not for him. Laufey had not had such madness in her eyes, and _that_ had been the illusion.

The Presence wavered outside of Loki’s sphere of influence—her total control over Space, Reality, Mind, and Soul, but even the Gems bowed beneath such an onslaught. Chthon’s malignancy had nothing on Thanos’; he was a shapeless, faceless blight, a curse upon reality. Cracks formed about him—

—but the universe had been broken a long time before he’d ever shown up.

_The Outsider,_ said Thanos. The words penetrated Loki's protection like thunder heralding a lightning strike: a rolling, distant echo, impressive but scarcely conveying the reality of plasma heated hotter than the surface of the sun. Outside of Loki's bubble of control, reality was melting. _You have been a thorn in my side for too long, pestering me constantly._

He was addressing Loki. Well, shit. Tony’d been wrong about Loki working for Thanos. Fucking icing on the cake.

Tony stared up at Steve—it wasn’t like he could look away. Steve couldn’t either; he was as unnaturally still as Tony was. They couldn’t twitch, couldn’t blink. They breathed because Loki willed it. _Jesus christ, I’m so sorry, Steve._

“Thanos,” said Loki. “I have a bargain to make with you.”

_Or, I was right — but too damn early..._

Thanos laughed. Loki’s grip on Tony’s mind flexed and wavered beneath that force, and he strained, clawed for freedom—it was the freedom of destruction, he knew; no mortal could really expect to last in that Presence. _Please —_ but his breath stopped and his heart beat sluggishly. He fell short.

_Is that why you have been flaring those Infinity Gems so brightly, trying to attract my attention? What do you possibly have to bargain with? The Gems are but a convenience to me._

“I have this,” said Loki, holding up one hand. Green light flared, not the shade of Loki’s magic, but something deeper, awfuller: the Soul Gem. A pinpoint of light appeared above Loki’s palm, gripped within the Gem’s power—but this near, Tony saw it, _recognized it_ —it resonated through his body and his mind, _mine mine mine mine MINE_

Thanos’ intrigued skepticism oozed past Loki’s wall. _A mortal soul? You must be joking._

_“This_ is the soul I anchored a very particular spell upon, when I ripped my home dominion to shreds and denied it the last gasp of Ragnarok,” said Loki. “I know what you seek, Thanos: Death Herself. You’ve waded through dominions one at a time, slaughtering them just as surely as you seek to slaughter this one. But _I_ hold an entire dominion at the brink of death, denying them that final fall—each passing moment, denying them renewal, denying them life! I hold death in the palm of my hand, Thanos. Do you think _that_ is worth bargaining for?”

Tony couldn’t breathe. Couldn’t move. Everything in him strained toward that light—the thing that should have been _his_ , that was him—he could barely think to wonder when Loki had stolen it, _how_ —

_You cannot withstand me. All of the Gems—perhaps, for a time, but only a short one. And you do not have them all. Break beneath me, little godling,_ said Thanos, and the weight of the parasite crushed down—it was grown fat, engorged on its host, and beneath it sickly reality began to smother.

“Wait,” said Loki, falling to her knees, but back unbent, head unbowed, “You will _not,_ Thanos, or I will just destroy it, and the chance to have it for yourself will be gone! You can’t—kill me—quick enough!”

Thanos laughed. Reality warped like a soap bubble. _You don't have the power._ _Even the Soul Gem cannot destroy a soul. It cannot destroy itself._

“Ah,” said Loki, grinning with all her teeth bared, “but my puppet here has a Nullifier. _That_ will destroy anything short of the Gems themselves. It may even be sufficient to break one apart.”

Reality straightened. The pressure eased. Thanos had paused.

“No gain for you, once this winks out. You’ll be back to going through each dominion one at a time... Death before you, Death in your wake, but never, ever in your _grasp_.”

_...Clever, Outsider._

“My terms are simple,” said Loki, breathing normally once again. She climbed back to her feet. “Easy. You will leave this dominion, as I’m sure you would anyway. You’ll want to fully enjoy your new acquisition.”

_Yes..._

“Will it bring you what you seek? I don’t know.” She shrugged. “But I’m sure it is worth a try... a chance is all I offer. You’ll leave me the Gem of Power in return.”

_Oh?_ Crimson light shone, a pin-point star nearly equal in power to that awful presence.

“Yes. It can’t be taken outside its dominion in any case, and I shall use it to leave myself.” Loki flashed a charming smile. “I don’t object to your return to this dominion, once I am gone, if your endeavours elsewhere don’t work out. But for our bargain, if you _do_ return, from here you will _not_ follow me. There are many other dominions to be devoured. Surely my terms would be no inconvenience.”

_Agreed_ , said Thanos, and logic shifted; reality shifted. The next moment Tony couldn’t process it. The thing that was him, that was his, was shining brightly at the end of Loki’s hand, an abstract concept given form and pulled away from the Soul Gem, and his soul could feel the Gem’s resentment at the loss of his prize and he could feel Loki’s will separating them until the two snapped and then his awareness of the Gem went out and all he could feel was horror at the grip of that Presence around him and crushing and

Leaving.

Loki’s harsh breathing echoed from the ruined walls of Laufey’s palace. Her grin grew wider, crazed—she turned toward Tony and Steve, insanity like fire in her eyes, as her form melted, reshaping into the image of the god who’d taken over Stark Tower a year ago—such a petty, puny alien. “So. You see? I did have a plan. He is _gone_ , as I promised, and this _cluster_ is safe, your world is safe, at least long enough for him to try his hand at the other—”

_And you’ll kickstart Ragnarok here, and burn it to ash leaving,_ Tony thought furiously.

Loki shrugged in response. “Well, yes. But that will take me some time to arrange—possibly less, if I can find the Time Gem. I _am_ curious to know where in all the hells you managed to lose it—a pity, even you don’t know. But I’ll have time to find out... I’ll be keeping you around, you see. It will take a while to see such a weighty entity as Thanos gone, and until then, I'll be able to call your soul back if he breaks his side of the bargain...” The Soul Gem danced over his fingers, flipping over each knuckle in turn before he made it vanish. “A bit of insurance. And, to be honest, a bit of amusement.” He crouched. The edges of his leather coat pooled against the floor. His smile was like knives.

_Oh_ _god, no, no no no no NO_ NO NO

“Yes,” murmured Loki. “Beg. I’ve been holding off, saving this for a special occasion. Go on, Tony. Beg me.” He grinned, and terror rose like bile through Tony’s chest as he opened his mouth to speak—

An orange point of light appeared overtop of the reactor in Tony’s chest.

Loki stopped with his mouth half-open, taken aback—and the shock loosed his grip just enough; desperation did the rest, and Tony slapped his hand over the Time Gem and threw himself _forward_ —one moment ahead of Loki’s control chasing him, just out of sync. His mind was half split across timeframes—Steve, freed of the control when all of Loki’s thoughts went to grabbing Tony again, overbalanced and nearly fell—Tony had already moved, and he watched as in the past, out of sync, Steve spun around and kicked Loki in the face, cracking Loki’s nose and his boot both.

Useless; Loki’s nose reformed unharmed, Reality bending to make it so, and Steve screamed as something inside _him_ began to—Tony grabbed him and threw him back along his own timeline, back past Thanos, back past Loki’s deception, back past coming to Jotunheim. Loki nearly caught him with a twist of Space that made dimensions shorten, but Tony danced forward in time, pulling the Ultimate Nullifier from subspace with Loki _right in front of him,_ his finger on the trigger—

_I can’t use it_ _,_ he realized, and froze in horror.

“It will take a while to see such a weighty entity as Thanos gone —”

“If Loki is slain, Ragnarok may yet complete... Like the serpent he birthed: cut off the head, and the body will die.”

If he pulled the trigger, destroyed Loki—destroyed them both on the sacrificial pyre of this reality—then the other cluster would finish collapsing. Thanos would call off his bargain and return to destroy this one.

Unless he was caught inside the collapse. Oshtur had said even Thanos could die, if a dominion—a multiverse cluster—died with him. Two deaths, the deaths of the greatest threat to the cluster, were now in the palm of Tony’s hand—two deaths, but he didn’t fucking know _when_ to go. How long would it take a being that filled clusters to move to another? The Time Gem was his—how much time did he _need_? He couldn’t skip too far ahead, couldn’t give Thanos time to leave _and return_ , not to mention what fucking _Loki_ would do—

“Lie down and die!” snarled Loki—Tony had nearly frozen too long. But Loki...

—opened his mouth—

He _had_ frozen too long. Those words would chase him through time, through intent, through all of creation—

Loki spoke, syllables harsh and flat in his mouth, and Tony’s knees gave way—

But there was nothing, no change, except extremis registering pressure against his knee and shin plates. There was no pain. There was _nothing_.

Tony’s hands flew up to his head—useless, he was wearing a helmet and gauntlets—but the headband wasn’t there. He thought the words himself, thought them with _intent_ , and there was nothing. The Makluan headband was gone.

_When the hell - ?!_

The headband was gone—the headband, that fucking _collar_ —was gone. Everything he’d feared most was _gone_ —and he still didn’t know how far in the future he needed to go.

Loki had stopped speaking, was frowning—had realized something else was not working out for him. Tony scrambled to control his thoughts, but one kept ringing around in his head, dazedly, _It’s gone thank fuck it’s gone it’s gone it’s GONE_ and he hadn’t even dared to hope for it in so long, had shoved it down, convinced himself it would chain him the rest of his undoubtedly short life. But it was gone, and he didn’t know what to do next—

“If you ever get that collar off your neck — ” 

Realization was like a cascade.

“I feel like we’ve had this conversation before.” 

“ _—_ every plan I had, it’s not going to work because he _knows_ , now! There’s nothing I can do against him!”

“I shan’t say we can speak freely, nor plan freely, not against an enemy so pervasive...” 

An orange point of light appeared overtop of the reactor in Tony’s chest. A miracle he’d not thought to look for, appearing just when he needed it most.

“It’s fixable, Tony. It’d take less time than you think. Don’t come back before then.” 

_I sent myself the Time Gem. There’s no one else I would have turned to. Not for this._ Not to destroy himself. Steve wouldn’t have let him, and to fire this weapon, he had to know—

“In two years — which you might say is ambitious, but it would take less time than you’d think — ” 

“ _—_ Don’t come back before then.” 

_Christ, I’m sorry, Pep. I always leave the crap jobs to you, even when I’m trying my hardest not to. Or think I am —_

Point-nine milliseconds was all he could spare for revelations. Time to act, not think. Tony looked up.

Loki was backing away, wariness in his eyes. A part of Tony exulted in it, even as he swore to himself _fuck need to reach him with the Time Gem fuck fuck fuck_ and he lunged forward with the Nullifier in one hand and the Time Gem in the other. Amethyst light crackled, the Space Gem ripping Loki away, across worlds. Tony flared power to his own portal devices and followed, so close behind that he could see each destination as Loki formed it—because he was literally one second ahead.

Loki wasn’t used to the Space Gem. Tony wasn’t used to the Time Gem, either, but it was nearly identical to the Space Gem and he’d had days of practice with that; it responded to him like he'd worked with it for years. Either the others weren’t as similar or Loki was a slow learner, because he was clumsy with it, and now Tony was the cat instead of the mouse. They raced through a world on fire, flames dancing high, past the wastes of Hel, the ruins of Maklu—images flickered by, each world barely more than a blur as Loki fled from it in turn... and stumbled, tripped too near to the Gap. The great roots of Yggdrasil reached down about them both and the dragon that Tony could not see curled beyond. Loki’s eyes widened—

Tony reached just near enough and snagged them both in the Time Gem’s grasp, hurtling them forward down the years. The not-stars around them blurred. Loki brought up a fistful of yellow fire—the Reality Gem—and the nothingness around them became _something_. Reality blossomed into existence, yellow and purple lights combined to form an entire world where none had been before, and Tony grinned at Loki, making him snarl. _Yeah, thanks for making sure I don’t take the cluster with us._

Loki raised the Reality Gem, and the rules of this world ran differently—extremis dropped away from Tony as the bonds between the nanites broke, unable to form. But he’d built the Nullifier with a manual control just in case, and as soon as there was reality between them and the Gap, his finger was already pulling the trigger. There was no one else around to learn what happened when all the Infinity Gems at once were caught in the field of an Ultimate Nullifier, and he couldn't have planned this better if he'd—

The Nullifier activated.

 

* * *

 

Tony landed back in his body, screaming. Dimly, he was aware that tears were rolling down his cheeks from eyes strained too far and too wide. Fake pain, false errors, but his limbs spasmed and thrashed, independent of his control, as the Makluan headband ripped him apart, slowly, thoroughly. Somewhere, the mantra was being said, and the headband detected it.

Nothing could save him from this. There was nowhere to run. He sobbed for air and respite, but found none. There was only enduring it, until sometime later—an eternity, 3.2 seconds—it was over. The mantra had stopped; the pain ceased.

Tony lay on the ground of a dead world and breathed. The pure clarity of knowledge he’d held for that infinite instant—that understanding of what was—would be—could be—faded beneath the constraints of mortality. He’d lost it, and sweet Jesus, he didn’t want to ever look again. Was that the association with pain? Would he have ended up screaming anyway? Could he have even seen it, without seeing also the faults that the headband induced?

It took longer, this time, for him to get his breath back. He found himself contemplating the ashy distances around him: plains only, although there were hills off in the distance. If there was a volcano, or volcanic vents, they were over the horizon and out of sight. Overall he might’ve considered it boring, once, but it was a hell of a lot more lively than Hel. Tony dragged himself to his knees, then his feet. Finer ash had gotten into all the seams of the suit by now, turning him vaguely grey when he stared down at himself—at the two Gems in his palm.

Not just Loki to deal with when he got back, he thought dazedly. Thanos, too. Foster’s Silencer wouldn’t be sufficient against Thanos—the White Tiger had told him, them, that: Thanos knew when he was spoken of under any name. That meant there was some mental component there, _intent_. If it was—he made himself stop thinking about it, before he could kill all his possibilities trying, if Thanos’ reach went _that_ far.

He couldn’t just go back. Loki would be waiting with a trap. The other Gems were already claimed.

There had been something he’d seen, in that eternity-in-an-instant, all the uncountable paths lying in front of him and the one he wanted decorated with neon lights. Infinity contained within a point. The breadth and depth of space and time open before him, and—

He didn’t want to look again, but he was going to have to, wasn’t he? Because of everything he'd seen, he thought—he was beginning to think—he could _almost_ still see it: actions and ripple effects combining, resonating through the past and future, until they added up to something that, just maybe, just _might_ count as a win.

The Time Gem could handle paradoxes up to a point. Had he already started?

First things first. He needed a way to hide; he couldn't find what he was looking for if he wasn't able to risk _looking_. Loki had the Mind Gem, and Thanos was... Thanos. The memory of that power, that _Presence_ , was enough to make his hands shake. Thanos had the Power Gem, but he didn't need it. To the Titan, it was just a useful trinket.

_Just like Loki thinks I am._

If Tony managed to do the near-impossible, and kill Loki... it would be nothing but empty revenge, unless he could figure out a way to bring down Thanos, too. He needed to hide. He needed—clues adding up and clicking into place in place—someone to hide him.

“Death devours all secrets... Have you come to bargain with me again?”

Thanos had grabbed the Power Gem almost as soon as there _was_ the Power Gem, but only almost. He hadn't been here from the _very_ beginning of the cluster. There was still time.

Tony closed his eyes, squeezed his hand shut around the Gems, and thought about the beginning of the universe.

 

* * *

 

Steve screamed as his insides tore. Bones detached from muscles, acid ripped its way out of his stomach, lungs shredded so that his scream turned to a gurgle. Dimly, through the pain, he was aware that this damage was worse than when he’d been getting bombarded with vita-rays, when he’d been infected with extremis, and when he’d nearly died of radiation poisoning. He would not survive this.

Then the pain was gone, reversing, replaced with ice-cold. Fleeting sensations of movement, all overlaid by a deep orange light, and he opened his eyes and took a gasping breath of air with miraculously whole lungs. Radio chatter in his ear, the click of keys, people speaking quickly, nervously, all laid overtop of the hum of equipment; the visual display of the enemy alien ships, Udarnik’s dwindling fleet, white-blue lights: the command centre on 3490, still in crisis. He looked around wildly and saw that Tony wasn’t there.

“Steven?” Sue asked. The infinity gauntlet was still on the table before her; she hadn’t picked it up. Her voice turned flat. “He left you behind.”

“No,” said Steve, “No, we went, Thanos showed up, but the Time Gem was there, somehow—how much time has it been here?”

Sue’s mouth moved: teeth almost bared, and it would have been a snarl had she not controlled the expression. “None at all. Anthony just left. But if Thanos’ attention is _there_ —”

“More than— _there_ , I think he _left_.” Steve shook his head. “Loki negotiated—but that’s in the future!”

“Thanos exists more than three dimensions, too,” said Sue. She wasn’t looking at Steve; she was looking at the display. “Reed? Tell me how this affects your calculations.”

Reed’s face cohered into something recognizable as a face, rather than eyeballs sitting on separate, wriggly stalks. He nodded. “I think—yes. Yes! Look at that, all the readings just changed—that’s impossible, they shouldn’t be able to drop discretely like that, it must be the Time Gem—”

Sue picked up the gauntlet.

A hush settled upon the control room. The chatter from the radio seemed remote; the visual displays, dim. Beneath the blue-white fluorescents, the gold of the gauntlet still seemed gaudy, tacky, but the gems themselves shone with recognizable power. When Sue pulled the gauntlet on, it fit to her skin like a glove: sized perfectly for her, and her alone. The lights of the gems shone brighter, then, coruscating about her hand, a torch of rainbow fire, visible _power_.

“ **The battle for this world is over,”** said Sue, and it was.

 

* * *

 

Five days later, representatives from twenty-seven Earths gathered in Stark Tower on Earth-3490, ostensibly to discuss the dissolution of Thanos’ fleets. The Sorceress Supreme of Earth-83437 was not among them; without their Earth’s infinity gauntlet, she had sacrificed her life to power a spell dismissing the fleet attacking her Earth. The Vision attended alone, his face blank with grief.

There were few others similarly grieving. The rest of the meeting had the air of a party more than a mutual briefing; there were some questions about the report that Steve had submitted for distribution among the allied Earths, but most people seemed more interested in celebrating than getting further details. There had been no reprisals, no further attacks. The scientists had confirmed that the Thanos-detection system they’d worked out was showing all clear—he was simply _gone,_ and the mystics and sorcerers all agreed. The Guardians of the Galaxy-3490 had reported in, confirming no other planets had been attacked, and this was confirmed across the other Earths, too.

There was catering, and somebody had definitely spiked one of the punch bowls.

“I’m sorry to hear about your Tony,” Steve-3490 told him in a quiet moment, and Steve nodded. He couldn’t quite make himself say anything in reply.

But he couldn’t avoid all the curious gazes once everyone was more or less gathered around the conference table. Or rather, that was until one of Wanda’s counterparts stepped up—another woman wearing that golden eye amulet—and said, gravely, “This must be the last time that our worlds all meet together like this.”

Steve blinked. Across the room, he could see others looking equally taken aback. Natasha, beside him, shot him a questioning glance—he shook his head. He had no idea what this was about.

And yet, it felt...

“Is there some new threat?” someone asked.

“No.” The Sorceress Supreme shook her head. “But Thanos is gone, and the walls between realities are rising once again. Perhaps the Living Tribunal has returned—perhaps not. With it or no, things are returning to as they once were.”

“But we can still keep these connections,” said Udarnaya, the Android who had stepped up to fill Udarnik's shoes. “We have much to learn from each other.”

“No. She’s right,” said Reed, stepping forward and waving an elongated hand at Toni. “Toni—thank you—” A display of equations appeared in the middle of the room, and about half the people there looked at it with interest, while the other half looked blank. “I’ve been looking into the reasons why inter-reality coordination was so much more difficult before this crisis. Cause and effect. Continuing to meet like this at regular intervals is working up a hill that is going to become much steeper very soon.”

“It’s true,” added another sorcerer—Sorcerer?—dressed in the same style. “Realities are meant to be separate. The walls of the multiverses must remain strong, and now they begin to again be patrolled by their intended watch-keepers. Observe, if you wish. Aid unfortunate travellers who have fallen astray. But interfere no more than that, or you will come to regret it.” Others around the table were nodding—Sorcerers. Mystics. Some of the Reeds and Sues. People who tapped alien power, and who had travelled between worlds before this crisis.

“Damn,” said Natasha, low enough that Steve alone heard her. But he glanced at her and saw the same awareness on her face that he felt himself. The walls were going up; some laws could not be denied. Everyone here had travelled realities at least once. There were some things that could be _felt_.

The meeting continued. When it finally broke up, Steve shook Reed’s hand, and Other-Steve’s and Toni’s and Sue’s, and knew that it would be for the last time.

 

* * *

 

“SWORD’s primary objective was always to monitor for threats from other worlds,” said Hill. “With the immediate threat of Thanos gone, our situation is a lot like it was one year ago. We have eyes on us not just from Asgard, but from a large number of other alien races. Those worlds will be opening their borders again, and we’ve attracted a lot of attention in the past year. Threats from other realities will be monitored and responded to, but our primary concern needs to be the worlds closest to home.”

_“These are valuable allies you’re talking about cutting off, here,”_ observed the WSC Chairman. _“A dialogue should be kept open, at the very least.”_

That was rich, Steve thought, after all the work he’d had to do to convince the WSC to start talking in the first place.

“Unfortunately, Chairman, they don’t agree. All Earths we’ve spoken to have already come to their own decision to cease inter-reality contact.”

It was a lie—the order of it, that was, not the end result. But Steve couldn’t read that from Hill’s expression. Apparently, neither could the Chairman, because he sighed but acceded to the point.

 

* * *

 

“I always liked the desert,” said Jane, pulling books out of the box she was packing and realigning them to make them fit. “I'm just not sure whether to be more surprised that they approved the funding or that they agreed to let me run it.”

“You're the most qualified person,” said Bruce. He didn't have a box; he hadn't made up his mind about whether or not he wanted to move out to Arizona to work in the facility SHIELD was renovating to provide a base for SWORD's new focus.

“I know that.”

“Xavier said you were fine,” said Steve. They'd managed to accomplish at least that much before that last meeting.

“Sure,” said Jane. She glanced toward the door, cautiously; it was a busy hallway outside. When she spoke again, she'd lowered her voice. “Do you believe it?”

Steve made himself try to smile. It came out more like a grimace. “Like he told me—Reality will prove itself with time.”

 

* * *

 

“Cap, either take the damn leave or I’ll bench you,” Fury told him.

 

* * *

 

He took a month’s leave, but stayed in New York. SHIELD wanted him to stay close so he could keep up his psych appointments, anyway. He was pretty sure that he was being watched, but he left the AED on and kept the curtains closed for the most part.

April turned to May, and suddenly it was the anniversary of the New York Invasion. Steve attended the city-hosted remembrance ceremony, but managed to get out of giving a speech.

The lingering billboards about the dangers of the Nanoplague finally vanished. International air travel picked up. A noted human rights’ activist spoke at the UN about the bombs dropped on Shenzhen, and people began getting paranoid about nukes and the Chinese instead. Steve went running around Central Park. Two paparazzi tried to snap shots the first day—until he swiftly outdistanced them—but by the fourth day they’d lost interest. He got a haircut, and when he wore sunglasses people looked past him with unrecognizing eyes.

Clint and Natasha each dropped by once, bringing news about the slow re-purposing of SWORD, and that—in Natasha’s case—she’d also been ordered to take leave. “Quite a lot,” she remarked wryly. “You got off lucky, Cap.” They clinked their beer bottles to that.

His neighbours changed out as agents got re-assigned and shuffled locations. He started considering moving out of the SHIELD-provided apartment, into someplace of his own, but it was strangely hard to contemplate. He thought that maybe if he were going on missions again, it wouldn’t be so bad, if he lived in the same place as the people on his team.

On his third week of leave, he was again in Central Park—with a sketchbook this time, not jogging—when a man sat down heavily on the bench next to him and said in a flat voice, “Sir.”

“Pardon?” said Steve, looking over. He’d only gotten approached the once last week. But this guy... looked like he could have done certain work for SHIELD. His face was expressionless, stiff—and vaguely familiar. Steve had seen him before, but not more than once or twice. When?

“I was asked to give this to you,” the man said. He proffered a thin document, two pages only, folded over in thirds, letter-style. The way he moved wasn’t exactly graceless, but it was strangely ponderous, like there was a hell of a lot of weight behind even the smallest motion.

“By who?” Steve asked, warily. He wished he was wearing gloves. The other guy was. Steve couldn’t see or smell any powder, but that was no guarantee. The pages were printer paper, thick enough that ink didn’t show through the other side.

The guy flipped them over. On the back, in familiar blocky writing, was, _FOR STEVE._

Steve’s breath caught. He studied the guy’s face more carefully—extremis? It didn’t _look_ like it: this guy had scars, tiny imperfections that looked real. When the hand holding the letter moved forward again, insisting, Steve accepted it.

“Please don’t follow me?” the guy asked, and it sounded painful, like asking a question was somehow difficult for him. His face was still blank. Shell-shocked.

Steve nodded, and flipped the paper open and straight. Beside him, the guy stood. The way he planted his feet made him look unbalanced, too heavy, and a ridiculous hope flared in Steve's heart.

Then fell. The first page on top—not the one which had _FOR STEVE_ written on the back—wasn’t in Tony’s hand.

_Captain Rogers,_ it read. _My name is Gina Dyson..._

Steve jerked his head around to follow the man’s retreating back—he was walking away at a brisk pace. Between one crowd of kids in hoodies and a family out for a walk, he vanished, but Steve recognized him now, from pictures he'd seen half a year ago. _Eric Savin._ Army Colonel, the superior officer of Lt. Dr. Gina Dyson at the time Project ULTRA-Tech had collapsed... supposedly dead and buried. Dyson had broken out of Leavenworth shortly after the Chitauri; she’d been one of the criminal scientists suspected of working for Tony in Shenzhen, but they’d found no trace of her there—and Tony had denied it, later, anyway.

Apparently, he’d been lying. Again.

_...Nine years ago, I started working with Tony Stark. He mentioned you used to live with him, so hopefully you won’t think I’m crazy when I tell you that was in 2013. It was a shock for me when I found out, too..._

Steve flipped the first page behind the second. It, too, was hand-written, but shorter than Dyson’s.

_Steve,_

_I’m sorry. In the end I guess I really can’t play well with others. If you’re reading this, and I’ve disappeared in a weird way, then yes, I’m probably dead. Hopefully our two big problems are too. I wish I could explain why, but it would be remarkably stupid for me to do that now and ruin all the effort I’ve put into secrecy._

_It’s stupid for me to be writing about any of this, really, but I need your help one last time. So long as we have our god-problem, I can’t reactivate JARVIS. I’m pretty sure there is a curse—you-know-who's fault. Aimed at me—long story. JARVIS doesn’t deserve to sit mindless in storage forever. Only one code is needed to activate this copy, but he will need more server space. Please help him. I can’t trust SHIELD with him, even with all the progress you’ve made with SWORD. Please help Pepper. I can’t trust SHIELD with her either. She needs backup._

_I’ve never pretended not to be a hypocrite. I know I’ve never been fair in what I’ve asked of others._

It wasn’t signed. Steve wasn’t even sure Tony had finished it.

Tony was dead. Tony _had_ _thought_ he was going to die. Tony... had had some secret plan again, and had carried it off and told no one. Except, apparently, Gina Dyson.

Steve sat on his bench and stared, unseeing, at the skyline for a very long time. Eventually, when his butt grew numb, he turned back to Dyson’s letter.

_...I never worked on any of his technology relating to time-travel, so that was a shock. As I have finished my contract with Tony, I am now taking a permanent vacation with my boyfriend, Eric Savin. As a personal favour, in exchange for sending this letter to you, I ask that you please refuse any requests to hunt us down. He would be used as a lab experiment by the military._

_Tony wrote many versions of the letter I’ve included. He trashed them all, but I finally stole one to see what he was doing. I’m glad I did. I had concerns about some other things he had planned, but if I hadn’t read that letter I don’t think I would have realized in time to stop him. There was a promise he made to me that he planned to break, you see. Fortunately, I was able to make substitutions that prevented him from doing so. I’m not sure if it actually escaped his notice, or if he decided to let it go, or if he forgot. He was very pre-occupied in the last few days._

_I hope that he is not dead, despite what was in the letter. I tried to ask if he was suicidal, but it was clear he didn’t want to talk about it. I’m not sure if I should have told him I had seen the letter. Maybe telling him would have made a difference._

_At West Point you were always held up as the highest ideal of moral behaviour. This was often the subject of jokes among the cadets, since we also studied the many occasions under which you went against orders... but you always had a good reason. You were idealized for maintaining values ahead of both your time and ours. Tony is very secretive, but I’ve heard a lot about you from him and nothing that contradicts that. I hope that I am doing the right thing by leaving this to you._

_I have moved everything I saved to a storage locker at 47.67, -122.10, unit 34. I’m not sure who JARVIS is, as I cannot get the case open myself, but I moved him there as well. I think that Tony had a plan to store him in another location for you to pick up, but decided not to go through with it. He did not attempt to destroy JARVIS, however, so I think he must be very important to him nonetheless._

_Please don’t look for us._

_Sincerely,  
Gina Dyson_

47.67, -122.10. That was northwest USA... Steve pulled out his phone and debated checking the maps, then hit the number for Natasha’s speed-dial instead.

_“Steve?”_

“Are you State-side?”

_“Not exactly. Why?”_

“There’s something I want to go check out.” _This line might be monitored._

_“Hm. I’ll see if Clint’s free to give me a ride.”_

“Good idea,” he breathed, and started gathering up his sketching materials for the run home.

 

* * *

 

Steve didn’t ask how Natasha and Clint had managed to procure a quinjet even though they were technically all on leave. He _did_ ask, “Does Fury—”

“He’s got an idea,” said Clint. “But he’ll let you run with it. You and your goddamn drama, Rogers. Only one worse than you is Tony.”

Despite the teasing, his expression was grim, and the flight out to the storage lot was silent. Clint stayed with the jet while Steve and Natasha went in—Natasha first, disabling the security system with practised ease. From there, unit 34 wasn’t difficult to find: each unit was a large shipping container with the number painted in large, professional letters on the sides and on the door: a bland, industrial barrier with an electronic lock that had only one pad, no buttons. Steve considered tapping the side of the container, to try and determine if it had been reinforced, and then thought better of it.

“He likes his hidey-holes,” Natasha muttered. “You should probably get the lock. The one in Oregon had defences.”

Considering what could happen if Dyson had a streak of paranoia even half as wide as Tony’s—“Right,” said Steve, and pressed his thumb to the pad.

There was a click, then the sound of a heavier bar retracting, but nothing beyond that. Either it was silent, or Dyson _wasn’t_ half as paranoid as Tony. Steve exchanged a glance with Natasha, and tried the handle, pushing the door gently inward.

_“Woah,”_ said Clint. _“Definite energy spike when you opened the door—bet there’s an arc reactor in there.”_

The inside of the storage container was only half-full, and well-lit by bright fluorescents that came on overhead as they entered. Metal boxes were stacked neatly up against the back wall, loading pallets separating each layer. They were closed, with no labels that he could see, no hint at what might be inside them, except that cables ran out of several of them. Most vanished into other boxes, but three—coloured red, blue, and yellow—ended in a neat coil on the wall.

On an adjacent wall were two three-foot high server-racks that took up half the remaining floor-pace. Carefully placed on top of the nearest was a familiar-looking suitcase, identical to the one that Pepper had worn cuffed to her wrist when she’d brought JARVIS’ backup right after Tony had... when they’d thought Tony had died. On the other rack was a small black box that Steve had never seen before.

“That’s the package,” said Natasha, crossing over quickly to the suitcase. “But no power source connected.” She inspected it carefully, and the cables on the wall. “If it’s like the other, then those cables aren’t for this.”

“They might be for this,” said Steve, looking over the back of the black box. There were ports at the back, with three coloured strips of electrician’s tape. Not the most difficult puzzle to solve, but he felt reluctant to tamper with it nonetheless.

Natasha nodded. Her expression was too blank for him tell what she was thinking.

“Do we do this here?”

She hesitated, and reached up to tap her radio off. “Steve... it’s a black box.”

“Yes—oh.”

A black box. A final record.

Natasha pulled out a small device and stuck it on the end of the server rack. “That’ll record it, if it’s needed. I’m going to wait outside.” She patted him awkwardly on the arm, and went out. The door clicked shut behind her.

“Radio check,” Steve tried, and heard only silence. If this place could shield the energy reading off of an arc reactor, it must be good enough to disrupt communications. Maybe Dyson had some paranoia in her after all.

With a lump in his throat, he took the coil of cables down from the wall, and slotted them into the ports on the box. For a moment, nothing happened. Then a small LED that Steve hadn’t seen on the front blinked on, a painfully bright point of red, and a lens clicked open.

_“What—Steve,”_ said Tony’s voice, and the lights flickered—and then he appeared. It was only an image of him, a hologram, but it was three-dimensional and painfully illuminated in full colour. Also, about nine inches high, and standing on top of the server rack. Tony looked down at himself in dismay. “Christ, midget does not look good on me.”

“Oh, I dunno,” said Steve. “You managed it pretty well for the first forty-two years of your life.” His voice wobbled.

“And grew myself to six foot at the first opportunity, you might have noticed,” Tony shot back, but his face had fallen. It was—weird. It wasn’t like watching someone on a screen, a tiny head on a tiny body—the hologram looked like the actual Tony Stark in front of him, just... shrunk.

And just an image.

“So, I don’t actually have a connection with the outside world here, that’s nice, you’ve stuck me somewhere shielded,” said Tony, now with a wary look on his face as he craned his neck up at Steve. “Fill me in, here.”

Steve went down on one knee, to put them on a more even eye-level. “You vanished. Nearly a month ago. We were—things went wrong, Thanos was invading, Loki tricked us—we were on Jotunheim and he had us cornered. Then... the Time Gem appeared, right over you. You grabbed it and sent me back in time, as far as I can tell. I woke up on another world confused as hell, nobody around me had any clue what had happened in that timeline. But you—never came back.”

“And Loki and Thanos?” Tony asked. “If you’re going to toss their names around—”

“Gone,” said Steve, and the relief that crossed Tony’s face was _so_ real... “We’ve got word from a few Asgards and Loki’s dead in all of them, although we don’t know about Asgard Prime. Thanos is gone, too—and... things are different. Crossing into other realities feels _different_. Something changed. The other Earths, they think things have gone back to how they were before.”

“Well,” said Tony. He sounded a little bit giddy. “Well. I win, then.”

“Yeah.” Steve tried for a smile, but it came out flat and bitter; he looked away. “Y’know, not twenty minutes before it happened—you know what you asked me? You asked me to trust you. And I did.”

“Steve—”

“I trusted you and I thought you trusted me,” Steve said doggedly, “and then this morning I get a letter from a woman I’ve never met telling me you were working on _something_ , this, for years, with the Time Gem, and you never—” His voice cracked. “And here you are. Another goddamn hologram, another goddamned secret plan. You’re not—Tony’s dead, and—I thought, before the end, he was starting to—to get better. But now you’re here and, God, he’s probably dead, died still paranoid and miserable and lying—”

He had to stop, then. His throat was too tight to keep speaking.

“Steve,” said the hologram, and it looked so goddamn distressed. “Steve—” Tony shook his head. “You don’t have all the pieces. The guy you know, the guy you... thought might be happy? He might’ve been. I don’t know. I’m... a program, yes, but I’m not based on the guy who was him. I, uh. Split myself.”

“You—what do you mean, _split yourself?”_

“Loki grabbed you,” said Tony. “He kidnapped you and Foster. When we went after you, I got the Space Gem, and I went after the Time Gem... and I found it. God, I found it.” His voice was haunted. “I ran away. To the future, as it turned out, but I wasn’t really thinking at the time. When I’d—well, stopped screaming—I figured that with the Time Gem, I could find the others. They’re all connected, right? They go right back to the beginning—they were all one thing, once.” He looked contemplative. “I don’t think they’re the pieces of a dead god, actually. I think... they’re what was before there was a living one. Maybe.”

“Tony,” Steve snapped.

“Sorry, that's a tangent. So I looked. And, uh. Saw what happened to them. Loki’d snuck his way into Maklu ages ago, stole the Soul Gem—he’d gone and ripped my soul out months before while I was half out of my head from extremis. See, that was the key—when he kicked off Ragnarok back in his cluster, he’d needed an outside catalyst and he used me, my soul. So there were two anchors for his spell, him and me, and, well, I guess he thought it would be easier to control my soul if I wasn’t in possession of it. Not sure why he didn’t just kill me after, except for laughs.” He swallowed.

Ridiculous image. Tony was made of light.

“So Loki had that one, and as it turns out, the Time and Space Gems can’t just spirit the others away from their owners, in the past or present. Something of the owner clings to it. The trick with the Reality Gem... well. You were there. The entire time. So was he. Neither of us were thinking for ourselves. I think, maybe, he always had it. There’re things like that, things that were because they _are—_ with the Time Gem involved it gets complicated like that.”

“And the Mind Gem...”

“Yeah. That was what he grabbed you and Jane to get, by the way, not the Power Gem. Thanos had that one, won it just after he first arrived here. It didn’t do much for him—he’s got power on a level equal to the cluster itself—but. I don’t know. Maybe he just thought it was good tactics.” Tony smiled bleakly. “Who can guess at the mind of a god?”

“So you saw... all this,” said Steve.

“Yeah. And I knew... Loki would grab everything. Mind Gem, Soul Gem. I had a weapon, I was pretty sure I could use to kill him if I got close enough—”

Steve closed his eyes. “You were always building weapons.”

“I needed them.”

“Yeah.”

“Right, well, I had the Ultimate Nullifier. Does what it sounds like—it can obliterate anything short of the Infinity Gems themselves, and maybe even them… if I could get close enough to use it without being mind-controlled by him. Tough order, especially once he read my mind and knew I had it, though I wasn’t certain he _had_ , at that point. But even if I managed _that,_ there was Thanos, and it was pretty clear from the look I got at the universe that our side was going to lose that war. But...” Tony spread his hands. “Loki had a plan to get Thanos to go away.”

“Using your soul.”

“Yup. And I could piggyback on that one, because if Thanos was off investigating _that_ cluster, he’d be destroyed when it collapsed—which is just about the only way to destroy a being that cosmically powerful. Since Loki was the other anchor for his own spell... kill him, and it would let that cluster finish collapsing, two birds with one stone.” He grinned fiercely, looking smugly self-satisfied. “And, hey! Took fifteen years, so many goddamn recalculations, but it fucking _worked!_ ”

Then his eyes refocused, back to Steve, and his expression smoothed out. “I needed a way to set up a trap that I wouldn’t know about—I stole that idea from watching what Loki did to you. So I grew a clone. I created a version of me that I didn’t know what I had planned, so even if Loki took a rummage with the Mind Gem, there’d be nothing to find. It took a hell of a long time to figure out how, human brains are tricky. That was what I needed Dyson for. Then... I hopped through time, setting it up. Some of this I know worked, because I saw the effects, some I'm guessing about. If I followed the plan, then I asked asked Pepper to help sometime after I created this record, although the plan's to tell her that going to wipe my memory, not that the memory had never existed for that him. But she’s always known how to manage me, she'll know—must've known—how to feed me just enough clues that I’d figure it out at the right time, later. Then I dumped new-me with the Mandarin, set to get rescued by you.” His voice, his posture was perfectly casual. “And here we are, so my clone must have figured things out on schedule.”

Steve closed his eyes. “And you’re dead.”

“Well... yes,” said Tony. “A Nullifier isn’t directional. It annihilates everything around it to its outer range, and its... nature, because of the impact it has on reality, it can’t be used remotely. It’s one of those laws of reality, like the Gems. Probably for the best, since I doubt any of us would have survived this long otherwise. And this was worth it, don’t you think?”

Steve opened his eyes again. Tony’s expression was uncertain. _Concerned—_

He felt his own eyes narrow. “And you’re left behind.”

“I was supposed to delete this,” Tony said, frowning now. “Christ. Setting up all those sleight-of-hands and I left a _record_? Sloppy.” Something on Steve’s face must have shown—“Christ, it’s not like that, I’m a program, okay? And yes, it sucked, to leave you not knowing what happened, I know I’m a shitty person, but the goddamn _risk—_ ”

“Was enough to kill yourself over?” Steve asked, and despite everything he could do, his voice still hitched in the middle.

“What—” Something, wariness, showed on Tony’s face, and then he shut it down. “No. It wasn’t like that. You remember the White Tiger?”

“That cat in Maklu?”

“Yeah. He said that Thanos knew when he was being talked about. That means it had to be about intent. How do you hide _intent?_ Actually, Loki gave me that idea, too—he went to Hel, to hide. So did I. But hiding from Thanos... it’s a bit trickier than ducking Thor. The price is higher.” He shrugged, uncomfortably. “I hadn’t done it yet, when I’d created this program—obviously. But the bottom line requires I go back and pay up sooner or later, and considering you’re standing here telling me it was successful, obviously I did.”

“God, Tony.”

“Original me had to die. Put it down as something else that's probably for the best.” His eyes were tired. “The loop’s cut, the last thing tying Thanos to this cluster gone before it ever began.”

“Leaving you behind.”

“Not real-me’s brightest moment, but I guess he was feeling sentimental,” said Tony, shoving his hands into the pockets of his jeans. “Like I said, he should have destroyed this program. Thanos is gone—was gone—from _now’s_ perspective, but while he was real, this was way too dangerous to justify its existence.”

“You tried,” said Steve quietly. “Gina Dyson wrote me a letter. She said there were things you were planning to do she didn’t agree with... and that she’d managed to trick you. Switch out a fake.”

“I guess she thought I owed you a record,” said Tony, equally quiet.

“Or maybe she didn’t want to stand by and watch a murder-suicide.”

“Steve.” Tony’s voice was gentle. “I’m not an AI. I’m just an imprint program. It’s not suicide, there’s no... me—”

“Your expression changes,” Steve said overtop of him, ruthlessly. “The concern. I thought you were just a hologram because of the first one you left, but that one didn’t _care_. Pepper was crying”—Tony flinched—“and it didn’t bat an eye. You just _told_ me you were making a clone—”

“—a clone who wouldn’t know _—_ ”

“—but human brains are tricky, huh? You were the first run.” He wanted to add, _Stop lying to me_ , and barely cut himself off in time. Instead, he made his voice quieter. “Tony. Trust me?”

Tony looked at him for a long, long moment, his head tilted. Steve counted his breaths, made himself breathe slowly. He could see Tony thinking—even though it was an image. He could lie. Maybe he couldn’t really shut himself off, without extremis. Maybe not even with it. Or maybe he was just tired.

_Tired_ , Steve decided, when Tony sighed.

“Yeah. I’m the prototype.”

Slowly, Steve nodded, trying to put his thoughts into order. There were a lot of things he could say, only about half of them helpful. Or maybe none of them would be helpful, because he didn’t understand at all. “Why?”

Tony shoved his non-existent hands into his non-existent pockets, and shrugged, expression unreadable.

The silence stretched out, until it was obvious that Tony wasn’t going to answer. Feeling like he was walking out on black ice, Steve asked, “So what was the plan? To sneak off to the internet, or...” He couldn’t quite make himself finish the sentence, not when he’d already seen the consequences twice over.

“Figured I’d stick to the original.”

“Don't.”

“I’ve been working at it for a long time. It was a pretty good plan. Saved the multiverse—”

“Bullshit.”

Tony didn’t say anything to that.

Steve flattened his hand against his knee, and pulled out his own pain, like Tony had suggested a long time ago to browbeat reporters. “I’ve seen two versions of you kill themselves, Tony, I _can’t_ do it a third time. Don’t make me.”

“Yeah, it was a shitty plan,” said Tony on a sigh, the words escaping quickly, like air from a punctured balloon. His eyes skittered sideways, away from Steve’s—from an overabundance of honesty, Steve thought with relief, rather than a lack. “I’m just... I’ve been at this, what, sixteen, seventeen years. I’m... tired.”

“You can get some rest,” said Steve, trying to keep from deflating himself with relief. “As a... I don’t know if you sleep like that.”

“Not really.”

“You could make yourself a body. We’d keep you safe, Tony. We did pretty good with your, um, clone.”

“Yeah. I, uh, I know.” Tony chewed on his lower lip. “I had a lot of time to go over things.”

“You have friends,” said Steve, as kind as he could make it without putting Tony’s back up. Or tripping one of his anxieties.

“And I’m honoured by that, Steve,” Tony said, this time meeting Steve’s eyes directly. Even with him only nine inches tall, the intensity there, the _sincerity_ , was almost uncomfortable. “But I... I don’t know what’s next. Unless it’s trying to fix the mistakes I made while trying to fix the earlier fuckups I made, and...” He seemed to run out of steam, and looked around at the cabinets of the storage cube, lost.

Steve raised an eyebrow. “It’s okay to take a break from atonement, you know. Especially after saving the multiverse.”

That got a half-smile that was almost a smirk. “Yeah. I won that one.”

“So,” said Steve, only slightly hesitantly. “Stick around, and enjoy it with us. We’ll figure out what we’re doing with it later.”

“Yeah,” said Tony. And then, stronger—tiredness now eclipsed by familiar determination—“Yeah.”

Steve smiled back, and let himself feel the victory.

 

* * *

 

Outside of the confines of existence, the ruined remnants of six fundamental concepts remained: shattered, broken... their pieces now all entwined. Their wills, inasmuch as abstractions had wills and then rather more, were made whole by their destruction. The pieces dropped through rents in Reality and filled them, straightened them. Geometries simplified, much as two soap bubbles might collapse into one larger, simpler sphere. It became as if the cracks had never been: smoothed over, perfectly forged, through all of Time and Space.

From outside of either, Something Else observed the repairs: flaws in the fundamental make-up, there since its creation, now fixed, almost entirely via internal workings—with some help from Death’s Suitor, that rampaging being who had eaten more than one cluster of multiverses, but which was now gone. In _this_ cluster, now repaired, the remains of six fundamental concepts were nearly used up. Crumbs, compared to what their reach had been.

Much less powerful. Much more stable. A spark touched them, and for a moment the concepts were as glass thrown into the heart of the sun. The six broken points of the universe were crushed inward, forged together by the heat of Something Greater than any star. From it emerged... balance.

The Living Tribunal re-entered creation, an aspect of itself in every reality and every world at the same time. Its death at the beginning of eternity was avenged, and now undone, and the flaw that had stretched across reality was gone.

The halls of the Infinite Embassy expanded once more, and the Tribunal turned to serve the purpose of its all-knowing God.

 

* * *

 

Tony sat on a boulder and rested his elbows on his knees, staring out at the hills before him. If he looked right, it sort of resembled Malibu—dry and scrubby. For a moment, he missed his house there with an ache that pulled at his bones. The ache was only half psychosomatic, considering the lack of sleep he’d had over the last week, but if he was going to feel constantly tired anyway, he might as well take advantage and not let it be _all_ psychosomatic.

The cloning work had been set back by a string of recent failures, and Dyson had finally snapped and insisted on a vacation. Since that would mean he’d have to watch her, constantly, while she was out in the wider world, he was taking advantage of the Time Gem to work in a vacation of his own first. He could always just reappear after the moment he left—or before it, but he didn’t feel much like talking to himself. It wasn’t really much of a vacation, but it was a change, which was supposed to be just as good, and if he stopped working—then he might as well just _stop_.

The array buried in front of him was one that he’d set up going nearly a millennia in either direction of his start point, scattered across thousands of worlds. That was a paltry sample of the universe, but in this case he was just trying to cast a wide net and didn’t care how big the holes in it were. He was more concerned about what crossed it, rather than what was inside it. By themselves, the arrays were just souped-up versions of the Thanos-detecting device that the SHIELD geeks had come up with.

Connecting to them with extremis, and then making use of the Time and Space Gems, however...

Causality and Reality were a massive snarled knot, but he could see the shape of how it would unravel, now, all tied to the course of the Time Gem rather than the universe outside it—how he could pull on a string and the entire thing would come undone and smooth everything back into place. It was a fucked up mess he couldn’t give himself credit for creating—he wasn’t even sure he could give Thanos credit for creating it—and Loki’s machinations, constantly changing to match his own, almost like Loki had a Time Gem, too, had kept tripping him up... but it was all in place, now. The arrays were the last pieces of the puzzle. Thanks to them, he knew exactly how long it would take Thanos to shift his multidimensional bulk out of the cluster, and he could calculate with confidence the amount of time it would take him to ensconce himself in the one Loki had left cold and dying. Considering the immense forces and distances involved, it wasn’t as long as Tony had thought it would be.

Now, when he and Dyson succeeded—and they would succeed; they had Time on their side—he could leave and kick off the rest of it like knocking down dominoes.

Or he could go back. Years of watching Loki from afar, and Tony had unravelled the traps that had Loki had left, located the lures, and finally managed to tease them apart without Loki figuring out the game was up and implementing something else. He'd worked it out. If he worked it through carefully enough, he might even be able to avoid Loki ever learning of the mantra.

He chased the thought around, testing the edges of it. He could go back, screw everything back up into a mess again—just for a chance to, what, see a friendly face?

When put like that, the self-indulgence of the idea became almost laughable.

Tony sighed, then climbed off his boulder and shook the Time Gem into his hand. He had a couple thousand arrays scattered across Time and Space to pick up and pack up, and then he needed to go give Dyson a chance at a vacation.

**Notes for the Chapter:**

> ~~SO. This is pretty much the end. I mean, there's one more chapter left, but it's just an epilogue. (If it doesn't get posted next week on time, it will be because I've set it on fire and decided to leave the fic at 19/19. Or possibly just got distracted by CA:CW--please, no spoilers in comments--but right now fire seems more likely. Who knew that epilogues were so damn hard? _Not me._ )~~ Update: Fuckit, the epilogue is getting its own one-shot. 
> 
> Whether or not it avoids incineration, the epilogue will contain no further time-travel shenanigans. So if there's something still confusing about the time travel or, well, anything else, please let me know. For the graphically-inclined, I have linked a cleaned-up version of the timeline map that I used to keep track of Tony [here](http://i.imgur.com/EdAmf24.png) and (more permanently) in the fic endnotes below. 
> 
> Time travel is a headache and I need to take a break from writing it. (I say, with a time-travel-based WIP next on my list...)

**Author's Note:**

> Thanks for reading! As always, comments and constructive criticism are both welcome. If you would like to contact me privately, feel free to send me a [tumblr ask](http://teykekeyte.tumblr.com/ask). 
> 
> I had had this at 20 chapters total, because I thought that the epilogue would work as an epilogue for this fic. But in the end it's more an epilogue for the entire series, and sticking it onto this fic, which follows its own internal chronological order, just grated at me (and changing the epilogue to work with that order was an exercise in extreme frustration). So it's now 19/19 and the epilogue is its own oneshot. 
> 
> Speaking of chronology, a cleaned up version of the timeline map that I used to keep track of Tony's timeline in this fic is available [here](http://i.imgur.com/EdAmf24.png).


End file.
